Here are the changes from version 20041109 to version 20051202.

Summary:
  + New license: BSD-style instead of GPL.
  + New platforms:
   o hppa: Debian Linux.
   o x86: MinGW.
  + Compiler.
   o improved exception history.
   o Command-line switches.
    * Added: -as-opt, -mlb-path-map, -target-as-opt, -target-cc-opt.
    * Deprecated: none.
    * Removed: -native, -sequence-unit, -warn-match, -warn-unused.
  + Language.
   o FFI syntax changes and extensions.
    * Added: _symbol.
    * Changed: _export, _import.
    * Removed: _ffi.
   o ML Basis annotations.
    * Added: allowFFI, nonexhaustiveExnMatch, nonexhaustiveMatch,
        redundantMatch, sequenceNonUnit.
    * Deprecated: allowExport, allowImport, sequenceUnit, warnMatch.
  + Libraries
   o Basis Library.
    * Added: Int1, Word1.
   o MLton structure.
    * Added: Process.create, ProcEnv.setgroups, Rusage.measureGC, 
        Socket.fdToSock Socket.Ctl.getError.
    * Changed: MLton.Platform.Arch.
   o Other libraries.
    * Added: ckit library, ML-NLFFI library, SML/NJ library.
  + Tools.
   o updates of mllex and mlyacc from SML/NJ.
   o added mlnlffigen.
   o profiling supports better inclusion/exclusion of code.

* 2005-11-19
  - Updated SML/NJ Library and CKit Library from SML/NJ 110.57.

* 2005-11-15
  - Fixed a bug in MLton.ProcEnv.setgroups.

* 2005-11-11
  - Fixed a bug in the interleaving of lexing/parsing and elaborating of
    ML Basis files, which would raise an unhandled Force exception on
    cyclic basis references.  Thanks to John Dias for the bug report.

* 2005-11-10
  - Fixed two bugs in Time.scan.  One would raise Time on a string with a
    large fractional component.  Thanks to Carsten Varming for the bug
    report.  The other failed to scan strings with an explicit sign
    followed by a decimal point.

* 2005-11-03
  - Removed MLton.GC.setRusage.
  - Added MLton.Rusage.measureGC.

* 2005-09-11
  - Fixed bug in display of types with large numbers of type
    variables, which could cause unhandled exception Chr.

* 2005-09-08
  - Fixed bug in type inference of flexible records that would show up
    as "Type error: variable applied to wrong number of type args"

* 2005-09-06
  - Fixed bug in Real.signBit, which had assumed that the underlying
    C signbit returned 0 or 1, when in fact any nonzero value is
    allowed to indicate the signbit is set.

* 2005-09-05
  - Added -mlb-path-map switch.

* 2005-08-25
  - Fixed bug in MLton.Finalizable.touch, which was not keeping alive
    finalizable values in all cases.

* 2005-08-18
  - Added SML/NJ Library and CKit Library from SML/NJ 110.55 to 
    standard distribution.
  - Fixed bug in Socket.Ctl.*, which got the endianness wrong on
    big-endian machines.  Thanks to Wesley Terpstra for the bug report
    and fix.
  - Added MLton.GC.setRusage.
  - Fixed bug in mllex, which had file positions starting at 2.  They
    now start at zero.

* 2005-08-15
  - Fixed bug in LargeInt.scan, which should skip leading "0x" and
    "0X".  Thanks to Wesley Terpstra for the bug report and fix.

* 2005-08-06
  - Additional revisions of FFI.
    Deprecated _export with incomplete annotation.
    Added _address for address of C objects.
    Eliminated address component of _symbol.
    Changed the type of the _symbol* expression.
    See documentation for more detail.

* 2005-08-06
  - Annotation changes.
    Deprecated: sequenceUnit
    Added: sequenceNonUnit

* 2005-08-03
  - Annotation changes.
    Deprecated: allowExport, allowImport, warnMatch
    Added: allowFFI, nonexhaustiveExnMatch, nonexhaustiveMatch, 
      redundantMatch
        
* 2005-08-01
  - Update mllex and mlyacc with SML/NJ 110.55+ versions.  This 
    incorporates a small number of minor bug fixes.

* 2005-07-23
  - Fixed bug in pass to flatten refs into containing data structure.
        
* 2005-07-23
  - Overhaul of FFI.
    Deprecated _import of C base types.
    Added _symbol for address, getter, and setter of C base types.
    See documentation for more detail.
        
* 2005-07-21
  - Update mllex and mlyacc with SML/NJ 110.55 versions.  This 
    incorporates a small number of minor bug fixes.
        
* 2005-07-20
  - Fixed bug in front end that allowed unary constructors to be used
    without an argument in patterns.

* 2005-07-19
  - Eliminated _ffi, which has been deprecated for some time.

* 2005-07-14
  - Fixed bug in runtime that caused getrusage to be called on every
    GC, even if timing info isn't needed.

* 2005-07-13
  - Fixed bug in closure conversion tickled by making a weak pointer
    to a closure.

* 2005-07-12
  - Changed {OS,Posix}.Process.sleep to call nanosleep() instead of
    sleep().
  - Added MLton.ProcEnv.setgroups.

* 2005-07-11
  - InetSock.{any,toAddr} raise SysErr if port is not in [0, 2^16).

* 2005-07-02
  - Fixed bug in Socket.recvVecFrom{,',NB,NB'}.  The type was too 
    polymorphic and allowed the creation of a bogus sock_addr.

* 2005-06-28
  - The front end now reports errors on encountering undefined or
    cyclicly defined MLB path variables.

* 2005-05-22
  - Fixed bug in Posix.IO.{getlk,setlk,setlkw} that caused a link-time
    error: undefined reference to Posix_IO_FLock_typ.
  - Improved exception history so that the first entry in the history
    is the source position of the raise, and the rest is the call
    stack.

* 2005-05-19
  - Improved exception history for Overflow exceptions.

* 2005-04-20
  - Fixed a bug in pass to flatten refs into containing data structure.

* 2005-04-14
  - Fixed a front-end bug that could cause an internal bug message of the
    form "missing flexInst".

* 2005-04-13
  - Fixed a bug in the representation of flat arrays/vectors that
    caused incorrect behavior when the element size was 2 or 4 bytes 
    and there were multiple components to the element (e.g. (char *
    char) vector).

* 2005-04-01
  - Fixed a bug in GC_arrayAllocate that could cause a segfault.

* 2005-03-22
  - Added structures Int1, Word1.

* 2005-03-19
  - Fixed a bug that caused Socket.Ctl.{get,set}LINGER to raise
    Subscript.  The problem was in the use of PackWord32Little.update,
    which scales the supplied index by bytesPerElem.

* 2005-03-13
  - Fixed a bug in CML mailboxes.

* 2005-02-26
  - Fixed an off-by-one error in mkstemp defined in mingw.c.

* 2005-02-13
  - Added mlnlffigen tool (heavily adapted from SML/NJ).

* 2005-02-12
  - Added MLNLFFI Library (heavily adapted from SML/NJ) to standard 
    distribution.

* 2005-02-04
  - Fixed a bug in OS.path.toString, which did not raise InvalidArc
    when needed.

* 2005-02-03
  - Fixed a bug in OS.Path.joinDirFile, which did not raise InvalidArc
    when passed a file that was not an arc.

* 2005-01-26
  - Fixed a front end bug that incorrectly rejected expansive valbinds
    with useless bound type variables.

* 2005-01-22
  - Fixed x86 codegen bug which failed to account for the possibility that
    a 64-bit move could interfere with itself (as simulated by 32-bit
    moves).

* 2004-12-22
  - Fixed Real32.fmt StringCvt.EXACT, which had been producing too
    many digits of precision because it was converting to a
    Real64.real.

* 2004-12-15
  - Replaced MLB path variable MLTON_ROOT with SML_LIB, to use a more
    compiler-independent name.  We will keep MLTON_ROOT aliased to
    SML_LIB until after the next release.

* 2004-12-02
  - Unix.create now works on all platforms (including Cygwin and MinGW).

* 2004-11-24
  - Added support for MLton.Process.create, which works on all
    platforms (including Windows-based ones like Cygwin and MinGW) and
    allows better control over std{in,out,err} for child process.

--------------------------------------------------------------------------------

Here are the changes from version 20040227 to 20041109.

Summary:
  + New platforms:
   o x86: FreeBSD 5.x, OpenBSD
   o PowerPC: Darwin (MacOSX)
  + Support for MLBasis files.
  + Support for dynamic libraries.
  + Support for Concurrent ML (CML).
  + New structures: Int2, Int3, ..., Int31 and Word2, Word3, ..., Word31.
  + A new form of profiling, -profile count.
  + A bytecode generator.
  + Data representation improvements.
  + MLton structure changes.
    o Added: share, shareAll
    o Changed: Exn, IntInf, Signal, Thread.
  + Command-line switch changes.
    o Deprecated: 
        -native (use -codegen)
        -sequence-unit (use -default-ann)
        -warn-match (use -default-ann)
        -warn-unused (use -default-ann)
    o Removed: 
        -detect-overflow
        -exn-history (use -const)
        -safe
        -show-basis-used
    o Added: 
        -codegen
        -const
        -default-ann
        -disable-ann
        -profile-branch
        -target-link-opt

* 2004-09-22
  - Extended _import to support indirect function calls.
        
* 2004-09-13
  - Made Date.{fromString,scan} accept a space (treated as zero) in
    the first character of the day of the month.

* 2004-09-12
  - Fixed bug in IntInf that could cause a seg fault.
  - Remove MLton.IntInf.size.

* 2004-09-05
  - Made -detect-overflow and -safe expert options.

* 2004-08-30
  - Added val MLton.share: 'a -> unit, which maximizes sharing in a
    heap object.

* 2004-08-27
  - Fixed bug in Real.toLargeInt.  It would incorrectly raise Option
    instead of Overflow in the case when the real was not an INF, but
    rounding produced an INF.
  - Fixed bugs in Date.{fmt,fromString,scan,toString}.  They
    incorrectly allowed a space for the first character in the day of
    the month.

* 2004-08-18
  - Changed MLton.{Thread,Signal,World} to distinguish between 
    implicitly and explicitly paused threads.
        
* 2004-07-28
  - Added support for programming in the large using the ML Basis
    system.

* 2004-07-11
  - Fixed bugs in ListPair.*Eq functions, which incorrectly raised
    the UnequalLengths exception.

* 2004-07-01
  - Added val MLton.Exn.addExnMessager: (exn -> string option) -> unit

* 2004-06-23
  - Runtime system options that take memory sizes now accept a "g"
    suffix indicating gigabytes.  They also now take a real instead of
    an integer, e.g. fixed-heap 0.5g.  They also now accept uppercase,
    e.g. 150M.

* 2004-06-12
  - Added support for OpenBSD.

* 2004-06-10
  - Added support for FreeBSD 5.x.

* 2004-05-28
  - Deprecated the -native flag.  Instead, use the new flag
    -codegen {native|bytecode|C}.  This is in anticipation of adding a
    bytecode compiler.

* 2004-05-26
  - Fixed a front-end bug that could cause cascading error to print a
    very large and unreadable internal bug message of the form
    "datatype ... realized with scheme Unknown".

* 2004-05-17
  - Automatically restart functions in the Basis Library that correspond
    directly to interruptable system calls.
        
* 2004-05-13
  - Added -profile count, for dynamic counts of function calls and branches.
  - Equate the types Posix.Signal.signal and Unix.signal.

* 2004-05-11
  - Fixed a bug with -basis 1997 that would cause type errors due to
    differences between types in the MLton structure and types in the
    rest of the basis library.

* 2004-05-01
  - Fixed a bug with sharing constraints in signatures that would
    sometimes mistakenly treat two structures as identical when they
    shouldn't have been.  This would cause some programs to be
    mistakenly rejected. 

* 2004-04-30
  - Added MLton.Signal.{handled,restart}.
        
* 2004-04-23
  - Added Timer.checkCPUTimes, and updated the Timer structure to
    match the latest basis spec.  Also fixed totalCPUTimer and
    totalRealTimer, which were wrong.

* 2004-04-13
  - Added MLton.Signal.Mask.{getBlocked,isMember}.
        
* 2004-04-12
  - Fix bug that mistakenly generalized variable types containing
    unknown types when matching against a signature.
  - Reasonable front-end error message when unification causes
    recursive (circular) type.

* 2004-04-03
  - Fixed bug in sharing constraints so that A = B = C means that all
    pairs AB, AC, BC are shared, not just AB and BC.  This matters in
    some situations.

* 2004-03-20
  - Fixed Time.now which was treating microseconds as nanoseconds.

* 2004-03-14
  - Fixed SSA optimizer bug that could cause the error "<type> has no
    tyconInfo property".

* 2004-03-11
  - Fixed Time.fromReal to raise Time, not Overflow, on
    unrepresentable times.

* 2004-03-04
  - Added structures Word2, Word3, ..., Word31.

* 2004-03-03
  - Added structures Int2, Int3, ..., Int31.
  - Fixed bug in elaboration of "and" with signatures, structures, and
    functors so that it now evaluates all right-hand sides before
    binding any left-hand sides.

--------------------------------------------------------------------------------
Here are the changes from version 20030716 to 20040227.

Summary:
  + The front end now follows the Definition of SML and produces
    readable error messages.
  + Added support for NetBSD.
  + Basis library changes tracking revisions to the specification.
  + Added structures: Int64, Real32, Word64.
  + File positions use Int64.
  + Major improvements to -show-basis, which now displays the basis in
    a very readable way with full type information.
  + Command-line switch changes.
    o Deprecated: -basis.
    o Removed: -lib-search, -link, -may-load-world, -static.
    o Added: -link-opt, -runtime, -sequence-unit, -show-def-use,
             -stop tc, -warn-match, -warn-unused. 
    o Changed: -export-header, -show-basis, -show-basis-used.
    o Renamed: -host to -target.
  + FFI changes.
    o Renamed _ffi as _import.
    o Added cdecl and stdcall attributes to _import and _export
      expressions. 
  + MLton structure changes.
    o Added: Pointer.
    o Removed: Ptrace.
    o Changed: Finalizable, IntInf, Platform, Random, Signal, Word.

* 2004-02-16
  - Changed -export-header, -show-basis, -show-basis-used to take a
    file name argument, and they no longer force compilation to halt.
  - Added -show-def-use and -warn-unused, which deal with def-use
    information.

* 2004-02-13
  - Added flag -sequence-unit, which imposes the constraint that in
    the sequence expression (e1; e2), e1 must be of type unit.

* 2004-02-10
  - Lots of changes to MLton.Signal: name changes, removal of
    superfluous functions, additional functions.

* 2004-02-09
  - Extended -show-basis so that when used with an input program, it
    shows the basis defined by the input program.
  - Added "stop" runtime argument.
  - Made -call-graph {false|true} an option to mlprof that determines
    whether or not a call graph file is written.

* 2004-01-20
  - Fixed a bug in IEEEReal.{fromString,scan}, which would improperly
    return INF instead of ZERO for things like "0.0000e123456789012345".
  - Fixed a bug in Real.{fromDecimal,fromString,scan}, which didn't
    return an appropriately signed zero for ~0.0.
  - Fixed a bug in Real.{toDecimal,fmt}, which didn't correctly handle
    ~0.0.
  - Report a compile-time error on unrepresentable real constants.

* 2004-01-05
  - Removed option -may-load-world.  You can now use -runtime
    no-load-world instead.
  - Removed option -static.  You can now use -link-opt -static
    instead.
  - Changed MLton.IntInf.size to return 0 instead of 1 on small ints.

* 2003-12-28
  - Fixed horrible bug in MLton.Random.alphaNumString that caused it
    to return 0 for all characters beyond position 11.

* 2003-12-17
  - Removed -basis as a normal flag.  It is still available as an
    expert flag, but its use is deprecated.  It will almost certainly
    disappear after the next release.

* 2003-12-10
  - Allow multiple @MLton -- runtime args in sequnce.  This makes it
    easier for scripts to prefix @MLton args without having to splice
    them with other ones.

* 2003-12-04
  - Added support for files larger than 2G.  This included changing
    Position from Int32 to Int64.

* 2003-12-01
  - Added structure MLton.Pointer, which includes a type t for
    pointers (memory addresses, not SML heap pointers) and operations 
    for loading from and storing to memory.

* 2003-11-03
  - Fixed Timer.checkGCTime so that only the GC user time is included,
    not GC system time.

* 2003-10-13
  - Added -warn-match to control display nonexhaustive and redundant
    match warnings. 
  - Fixed space leak in StreamIO causing the entire stream to be
    retained.   Thanks to Jared Showalter for the bug report and fix.

* 2003-10-10
  - Added "-stop tc" switch to stop after type checking.

* 2003-09-25
  - Fixed Posix.IO.getfl, which had mistakenly called fcntl with
    F_GETFD instead of F_GETFL.
  - Tracking basis library changes: 
    o Socket module datagram functions no longer return amount
      written, since they always write the entire amount or fail.  So,
      send{Arr,Vec}To{,'} now return unit instead of int.
    o Added nonblocking versions of all the send and recv functions,
      as well as accept and connect.  So, we now have:
      acceptNB, connectNB, recv{Arr,Vec}{,From}NB{,'},
      send{Arr,Vec}{,To}NB{,'}

* 2003-09-24
  - Tracking basis library changes:
    o TextIO.inputLine now returns a string option.
    o Slices used in Byte, PRIM_IO, PrimIO, Posix.IO, StreamIO
    o Posix.IO.readVec raises Size, not Subscript, with negative
      argument. 

* 2003-09-22
  - Fixed Real.toManExp so that the mantissa is in [0.5, 1), 
    not [1, 2).  The spec says that 1.0 <= man * radix < radix, which
    since radix is 2, implies that the mantissa is in [0.5, 1).
  - Added Time.{from,to}Nanoseconds.

* 2003-09-11
  - Added Real.realRound.
  - Added Char{Array,Vector}Slice to Text.

* 2003-09-11
  - OS.IO.poll and Socket.select now raise errors on negative
    timeouts.
  - Time.time is now implemented using IntInf instead of Int, which
    means that a much larger range of time values is representable.

* 2003-09-10
  - Word64 is now there.

* 2003-09-09
  - Replaced Pack32{Big,Little} with PackWord32{Big,Little}.
  - Fixed bug in OS.FileSys.fullPath, which mistakenly stopped as soon
    as it hit a symbolic link.

* 2003-09-08
  - Fixed @MLton max-heap, which was mistakenly ignored.  Cleaned up
    @MLton fixed-heap.  Both fixed-heap and max-heap can use copying
    or mark-compact collection.

* 2003-09-06
  - Int64 is completely there.
  - Fixed OS.FileSys.tmpName so that it creates the file, and doesn't
    use tmpnam.  This eliminates an annoying linker warning message.

* 2003-09-05
  - Added structures {LargeInt,LargeReal,LargeWord,Word}
                     {Array,Array2,ArraySlice,Vector,VectorSlice}
  - Fixed bug in Real.toDecimal, which return class NORMAL for
    subnormals.
  - Fixed bug in Real.toLargeInt, which didn't return as precise an
    integer as possible.

* 2003-09-03
  - Lots of fixes to Real functions.
    o Real32 is now completely in place, except for Real32.nextAfter
      on SunOS. 
    o Fixed Real.Math.exp on x86 to return the right value when
      applied to posInf and negInf.
    o Changed Real.Math.{cos,sin,tan} on x86 to always use a call to
      the C math library instead of using the x86 instruction.  This
      eliminates some anomalies between compiling -native false and
      -native true.
    o Change Real.Math.pow to handle exceptional cases in the SML
      code. 
    o Fixed Real.signBit on Sparcs.

* 2003-08-28
  - Fixed PackReal{,64}Little to work correctly on Sparc.
  - Added PackReal{,64}Big, PackReal32{Big,Little}.
  - Added -runtime switch, which passes arguments to the runtime via
    @MLton.  These arguments are processed before command line
    switches.
  - Eliminated MLton switch -may-load-world.  Can use -runtime
    combined with new runtime switch -no-load-world to disable load
    world in an executable.

* 2003-08-26
  - Changed -host to -target.
  - Split MLton.Platform.{arch,os} into MLton.Platform.{Arch,OS}.t.

* 2003-08-21
  - Fixed bug in C codegen that would cause undefined references to
    Real_{fetch,move,store} when compiling on Sparcs with -align 4.

* 2003-08-17
  - Eliminated -link and -lib-search, which are no longer needed.
    Eliminated support for passing -l*, -L*, and *.a on the command
    line.  Use -link-opt instead. 

* 2003-08-16
  - Added -link-opt, for passing options to gcc when linking.

* 2003-07-19
  - Renamed _ffi as _import.  The old _ffi will remain for a while,
    but is deprecated and should be replaced with _import.
  - Added attributes to _export and _import.  For now, the only
    attributes are "cdecl" and "stdcall".

--------------------------------------------------------------------------------
Here are the changes from version 20030711 to 20030716.

Summary:
  + Fixed several serious bugs with the 20030711 release.

* 2003-07-15
  - Fixed bug that caused a segfault when attempting to create an
    array that was too large, e.g
       1 + Array.sub (Array.tabulate (valOf Int.maxInt, fn i => i), 0)
  - mlton now checks the command line arguments following the file to
    compile that are passed to the linker to make sure they are
    reasonable.

* 2003-07-14
  - Fixed packaging for Cygwin and Sparc to include libgmp.a.
  - Eliminated bootstrap target.  The Makefile automatically
    determines whether to bootstrap or not.
  - Fixed XML type checker bug that could cause error: empty tyvars in
    PolyVal dec.

* 2003-07-12
  - Turned off FORCE_GENERATIONAL in gc.  It had been set, which
    caused the gc to always use generational collection.  This could
    seriously slow apps down that don't need it.

--------------------------------------------------------------------------------
Here are the changes from version 20030312 to 20030711.

Summary:
  + Added support for Sparc/SunOS using the C code generator.
  + Completed the basis library implementation.  At this point, the
    only missing basis library function is "use".
  + Added _export, which allows one to call SML functions from C.
  + Added weak pointers (via MLton.Weak) and finalization (via
    MLton.Finalizable).
  + Added new integer modules: Int8, Int16.
  + Better profiling call graphs
  + Fixed conversions between reals and their decimal representations
    to be correct using the gdtoa library.

* 2003-07-07
  - Profiling improvements
    o Eliminated mlton -profile-split.  Added mlprof -split.  Now the
      profiling infrastructure keeps track of the splits and allows
      one to decide which splits to make (if any) when mlprof is run,
      which is much better than having to decide at compile time.
    o Changed mlprof -graph to mlprof -keep, and changed the behavior
      so that -keep also controls which functions are displayed in the
      table.
    o Eliminated mlprof -ignore: it's behavior is now subsumed by
      -keep, whose meaning has changed to be more like -ignore on
      nodes that are not kept.
  - When calling gcc for linking, put -link args in same order as they
    appeared on the MLton command line (they used to be reversed).

* 2003-07-03
  - Making OS.Process.{atExit,exit} conform to the basis library spec
    in that exceptions raised during cleaners are caught and ignored.
    Also, calls to exit from cleaners cause the rest of cleaners to
    run.

* 2003-07-02
  - Fixed bug with negative IntInf constants that could cause compile
    time error message:
    "x86Translate.translateChunk ... strange Offset: base: ..."
  - Changed argument type of MLton.IntInf.Small from word to int.
  - Added fix to profiling so that the mlmon.out file is written even
    when the program terminates due to running out of memory.

* 2003-06-25
  - Added {Int{8,16},Word8}{,Array,ArraySlice,Vector,VectorSlice,Array2}
    structures.
        
* 2003-06-25
  - Fixed bug in IntInf.sign, which returned the wrong value for zero.

* 2003-06-24
  - Added _export, for calling from C to SML.

* 2003-06-18
  - Regularization of options.
        -diag --> -diag-pass
        -drop-pass takes a regexp
        
* 2003-06-06
  - Fixed bug in OS.IO.poll that caused it to return the input event
    types polled for instead of what was actually available.

* 2003-06-04
  - Fixed bug in known case SSA optimization that could case incorrect 
    results in compiled programs.
        
* 2003-06-03
  - Fixed bug in SSA optimizer that could cause the error message
        Type error: Type.equals
        {from = char vector, to = unit vector}
        Type error: analyze raised exception loopStatement: ...
        unhandled exception: TypeError

* 2003-06-02
  - Fixed Real.rem to work correctly on infs and nans.
  - Fixed bug in profiling that caused the function name to be omitted
    on functions defined by val rec.

* 2003-05-31
  - Fixed Real.{fmt,fromString,scan,toString} to match the basis
    library spec.
  - Added IEEEReal.{fromString,scan}.
  - Added Real.{from,to}Decimal.

* 2003-05-25
  - Added Real.nextAfter.
  - Added OS.Path.{from,to}UnixPath, which are the identity function
    on Unix.

* 2003-05-20
  - Added type MLton.pointer, the type of C pointers, for use with the
    FFI.

* 2003-05-18
  - Fixed two bugs in type inference that could cause the compiler to
    raise the TypeError exception, along with a lot of XML IL.
    The type-check.sml regression contains simple examples of what
    failed.
  - Fixed a bug in the simplifier that could cause the message:
    shrinker raised Prim.apply raised assertion failure: SmallIntInf.fromWord

* 2003-05-15
  - Fixed bug in Real.class introduced on 04-28 that cause many
    regression failures with reals when using newer gccs.
  - Replaced MLton.Finalize with MLton.Finalizable, which has a more
    robust approach to finalization.

* 2003-05-13
  - Fixed bug in MLton.FFI on Cygwin that caused Thread_returnToC to
    be undefined.

* 2003-05-12
  - Added support for finalization with MLton.Finalize.

* 2003-05-09
  - Fixed a runtime system bug that could cause a segfault.  This bug
    would happen after a GC during heap resizing when copying a heap,
    if the heap was allocated at a very low (<10M) address.  The bug
    actually showed up on a Cygwin system. 

* 2003-05-08
  - Fixed bug in HashType that raised "Vector.forall2" when the 
    arity of a type constructor is changed by simplifyTypes, but
    a newly constructed type has the same hash value.
        
* 2003-05-02
  - Switched over to new layered IO implementation, which completes
    the implementation of the BinIO and TextIO modules.

* 2003-04-28
  - Fixed bug that caused an assertion failure when generating a jump 
    table for a case dispatch on a non-word sized index with non-zero
    lower bound on the range.
        
* 2003-04-24
  - Added -align {4|8}, which controls alignment of objects.  With
    -align 8, memory accesses to doubles are guaranteed to be aligned
    mod 8, and so don't need special routines to load or store.

* 2003-04-22
  - Fixed bug that caused a total failure of time profiling with
    -native false.  The bug was introduced with the C codegen
    improvements that split the C into multiple files.  Now, the C
    codegen declares all profile labels used in each file so that they
    are global symbols. 

* 2003-04-18
  - Added MLton.Weak, which supports weak pointers.

* 2003-04-10
  - Replaced the basis library's MLton.hostType with
    MLton.Platform.arch and MLton.Platform.os.

* 2003-04
  - Added support for SPARC/SunOS using the C codegen.

* 2003-03-25
  - Added MLton.FFI, which allows callbacks to SML from C.

* 2003-03-21
  - Fixed mlprof so that the default -graph arg for data from
    -profile-stack true is '(thresh-stack x)', not '(thresh x)'.

--------------------------------------------------------------------------------
Here are the changes from version 20020923 to 20030312.

Summary:
  + Added source-level profiling of both time and allocation.
  + Updated basis library to 2002 specification.  To obtain the old
    library, compile with -basis 1997.
  + Added many modules to basis library: 
    BinPrimIO, GenericSock, ImperativeIO, INetSock, NetHostDB,
    NetProtDB, NetServDB, Socket, StreamIO, TextPrimIO, UnixSock.
  + Completed implementation of IntInf and OS.IO.

* 2003-02-23
  - Replaced -profile-combine wih -profile-split.

* 2003-02-11
  - Regularization of options.
        -l --> -link
        -L --> -lib-search
        -o --> -output
        -v --> -verbose

* 2003-02-10
  - Added option to mlton: -profile-combine {false|true}

* 2003-02-09
  - Added options to mlprof: -graph-title, -gray, -ignore, -mlmon,
        -tolerant.

* 2002-11 - 2003-01
  - Added source-level allocation and time profiling.  This includes
        the new options to mlton: -profile and -profile-stack.

* 2002-12-28
  - Added NetHostDB,NetProtDB,NetServDB structures.
  - Added Socket,GenericSock,INetSock,UnixSock structures.

* 2002-12-19
  - Fixed bug in signal check insertion that could cause some signals
    to be missed.  The fix was to add a signal check on entry to each
    function in addition to at each loop header.

* 2002-12-10
  - Fixed bug in runtime that might cause the message
        Unable to set cardMapForMutator.

* 2002-11-23
  - Added support for the latest Basis Library specification.
  - Added option -basis to choose Basis Library version.  Currently available
    basis libraries are 2002, 2002-strict, 1997, and none.
  - Added IntInf.{orb,xorb,andb,notb,<<,~>>} values.
  - Added OS.IO.{poll_desc,poll_info} types.
  - Added OS.IO.{pollDesc,pollToIODesc,infoToPollDesc,Poll} values.
  - Added OS.IO.{pollIn,pollOut,pollPri,poll,isIn,isOut,isPri} values.
  - Added BinPrimIO,TextPrimIO structures.
  - Added StreamIO,ImperativeIO functors.
        
* 2002-11-22
  - Fixed bug that caused time profiling to fail (with a segfault) when resuming
    a saved world. 

* 2002-11-07
  - Fixed bug in MLton.eq that could arise when using eq on functions.

* 2002-11-05
  - Improvements to polymorphic equality.  Equality on IntInfs, vectors,
    and dataypes all do an eq test first before a more expensive comparison.

* 2002-11-01
  - Added allocation profiling.  Now, can compile with either -profile alloc
    or -profile time.  Renamed MLton.Profile as MLton.ProfileTime.  Added
    MLton.ProfileAlloc.  Cleaned up and changed most mlprof option names.

* 2002-10-31
  - Eliminated MLton.debug.
  - Fixed bug in the optimizer that affected IntInf.fmt.  The optimizer
    had been always using base 10, instead of the passed in radix.

* 2002-10-22
  - Fixed Real.toManExp so that the mantissa is in [1, 2), not [0.5, 1).
  - Added Real.fromLargeInt, Real.toLargeInt.
  - Fixed Real.split, which would return an incorrect whole part due to
    the underlying primitive, Real_modf, being treated as functional instead
    of side-effecting.

* 2002-09-30
  - Fixed rpath problem with packaging.  All executables in packages previously
    made had included a setting for RPATH.

--------------------------------------------------------------------------------

Here are the changes from version 20020410 to 20020923.

Summary:
  + MLton now runs on FreeBSD.
  + Major runtime system improvements.  The runtime now implements
    mark-compact and generational collection, in addition to the copying
    collection that was there before.  It automatically switches between
    the the collection strategies to improve performance and to try to avoid
    paging.
  + Performance when compiling "-exn-history true" has been improved.
  + Added IntInf.log2, MLton.GC.pack, MLton.GC.unpack.
  + Fixed bug in load world that could cause "sread failed" on Cygwin.
  + Fixed optimizer bug that could cause "no analyze var value property"
    message. 

* 2002-09
  - Integrated Sam Rushing's changes to port MLton to FreeBSD.

* 2002-08-25
  - Changed the implementation of exception history to be completely functional.
    Now, the extra field in exceptions (when compiling -exn-history true) is a
    string list instead of a string list ref, and raise conses a new exception
    with a new element in the list instead of assigning to the list.  This 
    changes the semantics of exception history (for the better) on some
    programs. See regression/exnHistory3.sml for an example.  It also
    significantly improves performance when compiling -exn-history true.

* 2002-07 and 2002-08
  - Added generational GC, and code to the runtime that automatically turns it
    on and off.
    
* 2002-08-20
  - Fixed SSA optimizer bug that could cause the following error message
        x_0 has no analyze var value property 

* 2002-07-28
  - Added MLton.GC.{pack,unpack}.  pack shrinks the heap so that other processes
    can use the RAM, and its dual, unpack, resizes the heap to the desired size.

* 2002-06 and 2002-07
  - Added mark compact GC.
  - Changed array layout so that arrays have three, not two header words.
      The new word is a counter word that preceeds the array length and header.
  - Changed all header words to be indices into an array of object descriptors.

* 2002-06-27
  - Added patches from Michael Neumann to port runtime to FreeBSD 4.5.

* 2002-06-05
  - Output file and intermediate file are now saved in the current directory
    instead of in the directory containing the input file.

* 2002-05-31
  - Fixed bug in overloading of / so that the following now type checks:
        fun f (x, y) = x + y / y

* 2002-04-26
  - Added back max-heap runtime option.

* 2002-04-25
  - Fixed load/save world so that they use binary mode.  This should fix the
    "sread failed" problem that Byron Hale saw on Cygwin that caused mlton to
    fail to start.
  - Added IntInf.log2.
  - Changed call to linker to use libgmp.a (if it exists) instead of libgmp.so.
    This is because the linker adds a dependency to a shared library even if
    there are no references to it

* 2002-04-23
  - Rewrote heap resizing code.  This fixed bug that was triggered with large
    heaps and could cause a spurious out of memory error.
  - Removed gmp from MLton sources (again :-).

--------------------------------------------------------------------------------

Here are the changes from version 20011006 to version 20020410.

* 2002-03-28
  - Added BinIO.

* 2002-03-27
  - Regularization of options
        -g      -->     -degug {false|true}
        -h n    -->     -fixed-heap n
        -p      -->     -profile {false|true}

* 2002-03-22
  - Set up the stubs so that MLton can be compiled in the standard basis
    library, with no MLton structure.  Thus it is now easy to compile MLton
    with an older (or newer) version of itself that has a different MLton 
    structure.

* 2002-03-17
  - Added MLton.Process.{spawn,spawne,spawnp}, which use primitives when 
    running on Cygwin and fork/exec when running on Linux.

* 2002-02 - 2002-03
  - Added the ability to cross-compile to Cygwin/Windows.

* 2002-02-24
  - Added gmp back for use with Cygwin.

* 2002-02-10
  - Reworked object header words so that Array.maxLen = valOf Int.maxInt.  
    Also fixed a long-standing minor bug in MLton, where
    Array.array (Array.maxLen, ...) would raise Size instead of attempting
    to allocate the array.  It was an off-by-one error in the meaning of 
    Array.maxLen.

* 2002-02-08
  - Modifications to runtime to behave better in situations where the amount of
    live data is a signifant fraction of the amount of RAM, based on code from
    PolySpace.  MLton executables by default can now use more than the
    available amount of RAM.  Executables will still respect the max-heap
    runtime arg if it is set. 

* 2002-02-04
  - Improvements to runtime so that it fails to get space, it attempts to get 
    less space instead of failing.  Based on PolySpace's modifications.
  - Added MLton.eq.

* 2002-02-03
  - Added MLton.IntInf.gcd.
  - Removed gmp from MLton sources.  We now link with /usr/lib/gmp.a.
  - Added TextIO.getPosOut.
  - Renamed type MLton.Itimer.which to MLton.Itimer.t and 
    MLton.Itimer.whichSignal to MLton.Itimer.signal.
  - Added -coalesce flag, for use with the C backend.

* 2002-01-26
  - Added -show-basis-used, which prints out the parts of the basis library 
    that the input program uses.
  - Changed several other flags (-print-at-fun-entry, -show-basis, -static)
    to follow the {false|true} convention.

* 2002-01-22
  - Improved MLton.profile so that multiple profile arrays can exist
    simultaneously and so that the current one being used can be set from
    the SML side.

* 2002-01-18
  - The MACHINE IL has been replaced with an RSSA (representation explicit SSA)
    IL and an improved MACHINE IL.  

* 2002-01-16
  - Added known case SSA optimization

* 2002-01-14
  - Added rudimentary profiling control from with a MLton compile program via the
    MLton.Profile structure.

* 2002-01-09
  - Fixed bug in match compiler that caused case expressions on datatypes
    with redundant cases to be compiled incorrectly.

* 2002-01-08
  - Added redundant tuple construction elimination to SSA shrinker.
  - Improved flatten SSA optimization.

* 2001-12-06
  - Changed the interface for MLton.Signal.  There is no longer a separate
    Handler substructure.  This was done so that programs that just use
    default and ignore signal handlers don't bring in the entire thread
    mechanism.

* 2001-12-05
  - Added local ref elimination SSA optimization.

* 2001-11-19
  - The CPS IL has been replaced with an SSA (static-single assignment) IL.
    All of the optimizations have been ported from CPS to SSA.

* 2001-10-24
  - Fixed bug in Thread_atomicEnd -- limit was mistakenly set to base instead of
    to 0.  This caused assertion failures when for executables compiled -g
    because GC_enter didn't reset the limit.
  - Fixed bug in register allocation of byte registers.

* 2001-10-23
  - Added -D option to cmcat for preprocessor defines.  Thanks to Anoq for
    sending the code.
  - Changed limit check insertion so that limit checks are only coalesced within
    a single basic block -- not across blocks.  This slows many benchmarks down,
    but is needed to fix a bug in the way that limit checks were coalesced across
    blocks.  Hopefully we will figure out a better fix soon.

* 2001-10-18
  - Fixed type inference of flexrecord so that it now follows the Definition.
    Many programs containing flexrecords were incorrectly rejected.  Added many
    new tests to regression/flexrecord.sml.
  - Changed the behavior of -keep dot combined with -keep pass for SSA passes.
    Dot files are now saved for the program before and after, instead of just
    after.

* 2001-10-11
  - Fixed a bug in the type inference that caused type variables to be
    mistakenly generalized.  The bug was exposed in Norman Ramsey's sled.sml.
    Added a test to regression/flexrecord.sml to catch the problem.

--------------------------------------------------------------------------------

Here are the changes from version 20010806 to version 20011006.

Summary:
   + Added MLton.Exn.history, which is similar to SMLofNJ.exnHistory.
   + Support for #line directives of the form (*#line line.col "file"*).
   + Performance improvements in native codegenerator.
   + Bug fixes in front-end, optimizer, register allocator,
     Real.{maxFinite, minPos, toManExp}, and in heap save and restore.

* 2001-10-5
  - Fixed a bug in polymorphic layered patterns, like
        val 'a a as b = []
    These would always fail due to the variable "a" not being handled correctly.
  - Fixed the syntax of "val rec" so that a pattern is allowed on the left-hand
    side of the =.  Thus, we used to reject, but now accept, the following.
        val rec a as b as c = fn _ => ()
        val rec a : unit -> unit : unit -> unit = fn () => ()
    Thanks again to Andreas Rossberg's test files.  This is now tested for in
    valrec.sml.
  - Fixed dynamic semantics of "val rec" so that if "val rec" is used to
    override constructor status, then at run time, the Bind exception is raised
    as per rule 126 of the Definition.  So, for example, the following program
    type checks and compiles, but raises Bind at run time.
        val rec NONE = fn () => ()
        val _ = NONE ()
    Again, this is checked in valrec.sml.
  - Added '\r\n' to ml.lex so that Windows style newlines are acceptable in 
    input files.

* 2001-10-4
  - Fixed bug in the implementation of "open" declarations, which in the case of
    "open A B" had opened A and then looked up B in the resulting environment.  
    The correct behaviour (see rule 22 of the Definition) is to lookup each
    longstrid in the current environment, and then open them all in sequence. 
    This is now checked for in the open.sml regression test.  Thanks to Andreas
    Rossberg for pointing this bug out.
  - Fixed bug that caused tyvars of length 1 (i.e. ') to be rejected.  This is
    now checked in the id.sml regression test.  Again, thanks to Andreas
    Rossberg for the test.

* 2001-10-2
  - Fixed bugs in Real.toManExp (which always returned the wrong result because
    the call to frexp was not treated as side-effecting by the optimizer) and
    in Real.minPos, which was zero because of a mistake with extra precision
    bits.

* 2001-10-1
  - Added MLton.Exn.history.
  - Fixed register allocation bug with fucom instruction.  Was
    allowing fucomp when the first source was not removable.
  - Changed Real.isFinite to use the C math.h finite function.  This fixed the
    nontermination bug which occurred in any program that used Real.maxFinite.

* 2001-9-22
  - Bug fixes found from Ramsey's lrtl in contify.fun and unused-args.fun, both
    of which caused compile-time exceptions to be raised.

* 2001-9-21
  - Fixed MLton.World.{load,save} so that the saved world does not store the
    max heap size.  Instead, the max heap size is computed upon load world in
    exactly the same way as at program startup.  This fixes a long standing (but
    only recently noticed) problem in which mlton (which uses a saved world)
    would attempt to use as much memory as was on the machine used to build
    world.mlton.

* 2001-8-29
  - Overlow checking is now on by default in the C backend.  This is a huge
    performance hit, but who cares, since we never use the C backend except for
    testing anyways.

* 2001-8-22
  - Added support for #line directives of the form
        (*#line line.col "file"*)
    These directives only affect error messages produced by the parser and 
    elaborator.   

* 2001-8-17
  - Fixed bug in removeUnused optimzation that caused the following program to
    fail to compile.
        fun f l = case l of [] => f l | _ :: l => f l
        val _ = f [13]

* 2001-8-14
  - New x86-codegen infrastructure.
    o support for tracking liveness of stack slots and carrying them 
       in registers across basic blocks
    o more specific Entry and Transfer datatypes to make calling convention
       distinctions more explicit
    o new heuristic for carrying values in registers across basic blocks
       (look Ma, no Overflows!)
    o new "predict" model for generating register allocation hints
    o additional bug fixes

* 2001-8-7
  - MLton.Socket.shutdownWrite flushes the outstream.

--------------------------------------------------------------------------------

Here are the changes from version 20010706 to version 20010806.

Summary:
    + Word.andb (w, 0xFF) now works correctly
    + MLton.Rusage.rusage has a patch to work around a linux kernel bug
    + Programs of the form "exp ; program" are now accepted
    + Added the "MLton.Rlimit" structure
    + Added the "-keep dot" flag, which produces call graphs,
      intraprocedural control-flow graphs, and dominator trees

* 2001-8-6
  - Added simple common block elimination CPS optimization.

* 2001-8-2
  - Took out -keep il.

* 2001-7-31
  - Performance improvements to TextIO.{input, output, output1}

* 2001-7-25
  - Added redundant-test elimination CPS optimization.

* 2001-7-21
  - Added common-subexpression elimination CPS optimization.

* 2001-7-20
  - Bug fix to x86 codegen.  The commuteBinALMD peephole optimization would
    rewrite  mov 2,Y; add Y,Y  as  mov Y,Y; add 2,Y.  Now the appropriate
    interference checks are made.
  - Added intraprocedural unused argument removal.
  - Added intraprocedural flattener.  This avoids some stupid tuple
    allocations in loops.  Decent speedup on a few benchmarks
    (count-graphs, psdes-random, wc-scanStream) and no noticeable
    slowdowns.
  - Added -keep dot flag.

* 2001-7-17
  - Modified grammar to properly handle val rec.  There were several problems.
    o MLton had accepted "val rec 'a ..." instead of "val 'a rec ..."
    o MLton had not accepted "val x = 13 and rec f = fn () => ()"
    o MLton had not accepted "val rec rec f = fn () => ()"
    o MLton had not accepted "val rec f = fn () => () and rec g = fn () => ()"

* 2001-7-16
  - Workaround for Linux kernel bug that can cause getrusage to return a wrong
    system time value (low by one second).  See fixedGetrusage in gc.c.
  - Bug fix to x86 codegen.  The register allocator could get confused when
    doing comparisons of floating point numbers and use the wrong operand. 
    The bug seems to have never been detected because it only happens when both
    of the operands are already on the floating point stack, which is rare,
    since one is almost always in memory since we don't carry floating point
    values in the stack across basic blocks.
  - Added production to the grammar on page 58 of the Definition that had been
    missing from MLton since day one.
                program ::= exp ; <program>
    Also updated docs to reflect change.
  - Modified grammar to accept the empty program.
  - Added -type-check expert flag to turn on type checking in ILs.

* 2001-7-15
  - Bug fix to the algebraic simplifier.  It had been rewriting
                Word32.andb (w, 0wxFF) to w
    instead of  Word32.andb (w, 0wxFFFFFFFF) to w.

* 2001-7-13
  - Improved CPS shrinker so that if-tests where the then and else branch jump
    to the same label is turned into a direct jump.
  - Improved CPS shrinker (Prim.apply) to handle constructors
        A = A --> true
        A = B --> false
        A x = B y --> false
  - Rewrote a lot of loops in the basis library to use inequalities instead of
    equality for the loop termination test so that the (forthcoming) overflow
    detection elimination will work on the loop index variable.

* 2001-7-11
  - Fixed minor bugs in Array2.{array,tabulate}, Substring.{slice} that caused 
    the Overflow exception to be raised instead of Size or Subscript
  - Fixed bug in Pack32Big.update that caused the wrong location to be updated.
  - Fixed several bugs in Pack32{Big,Little}.{subArr,subVec,update} that caused
    Overflow to be raised instead of Subscript.  Also, improved the
    implementation so that bounds checking only occurs once per call (instead of
    four times, which was sometimes happening.
  - Fixed bugs in Time.{toMilliseconds,toMicroseconds} that could cause 
    a spurious Overflow exception.
  - Fixed bugs in Time.{fromMilliseconds,fromMicroseconds} that could cause
    a spurious Time exception.
  - Improved Pack32.sub* by reordering the orbs.
  - Improved {Int,IntInf}.mod to increase chances of constant folding.
  - Switched many uses of +, -, * in basis library to the non-overflow checked
    versions.  Modules changed were: Array, Array2, Byte, Char, Int, IntInf, 
    List, Pack32{Big,Little}, Util, String, StringCvt, Substring, TextIO, Time,
    Vector.
  - Added regression tests for Array2, Int (overflow checking), Pack32, 
    Substring, Time.
  - Changed CPS output so that it includes a dot graph for each CPS function.

* 2001-7-9
  - Change OS.Process.exit so that it raises an exception if the exit status
    is not in [0, 256).
  - Added MLton.Rlimit to provide access to getrlimit and setrlimit.

--------------------------------------------------------------------------------

Here are the changes from the 20000906 version to the 20010706 version.

Summary:
    + Native X86 code generator (instead of using gcc)
    + Significantly improved compile times 
    + Significantly improved run times for generated executables
    + Many bug fixes
    + Correct raising of the Overflow exception for integer arithmetic
    + New modules in the MLton structure

* 2001-7-6
  - GC mods from Henry.  Mostly adding inline declarations.

* 2001-7-5
  - Fixed several runtime bugs involving threads, critical sections, and
    signals.

* 2001-6-29
  - Fixed performance bug in cps/two-point-lattice.fun that caused quadratic
    behavior.  This affects the raise-to-jump and useless analayses.  In
    particular, the useless analysis was blowing up when compiling fxp.

* 2001-6-27
  - Henry improved wordAlign -- this sped up GC by 27% (during a self compile).

* 2001-6-20
  - Moved MLton.random to MLton.Random.rand and added other stuff to
    MLton.Random
  - Added MLton.TextIO.mkstemp.
  - Made Int.{div,quot} respect the -detect-overflow switch.

* 2001-6-20
  - Added MLton.Syslog.

* 2001-6-7
  - Fixed bug in MLton.Socket.accept that was in the runtime implementation
    Socket_accept.  It did a setsockopt SO_REUSEADDR after the accept.  It
    should have been after the call to socket in Socket_listen.  Thanks to
    Doug Bagley for the fix.

* 2001-5-30
  - Fixed bug in remove-unused that caused polymorphic equality to return 
    true sometimes when constructors were never used in a pattern match.
    For example, the following (in which A and B are not used as patterns):
        datatype t = A | B
        datatype u = C of t
        val _ = if C A = C B then raise Fail "bug" else ()

* 2001-3-27
  - Fixed bug that caused all of the following to fail
        {LargeWord,Word,SysWord}.{toLargeInt,toLargeIntX,fromLargeInt}
    The problem was the basis library file integer/patch.sml which fixed Word32
    but not the other structures that are the same.

* 2001-2-12
  - Fixed bug in match compiler that caused it to spend a lot of extra time in
        deep patterns.  It still could be exponential however.  Hopefully this
        will get fixed in the release after next.
        This bug could cause very slow compile times in some cases.
        Anyways, this fix cut the "finish infer" time of a self compile down
        from 22 to under 4 seconds.  I.E. most of the time used to be spent due
        to this bug.

* 2001-2-6
  - Fixed bug in frontend that caused the wrong file and line number to be
        reported with errors in functor bodys.

* 2001-1-3 - 2000-2-5
  - Changes to CoreML, XML, SXML, and CPS ILs to replace lists by vectors in
        order to decrease space usage.

* 2001-1-16
  - Fixed a bug in constant propagation where the length of vectors was not
        propagated properly.

* 2000-12-11 - 2001-1-3
  - Major rewrite of elaborator to use a single hash table for each namespace
        instead of a hash table for every environment.

* 2000-12-20
  - Fixed some bugs in the SML/NJ compatibility library,
        src/lib/mlton-subs-in-smlnj.

* 2000-12-8
  - More careful removal of tracing code when compiling MLton_debug=0.
    This cut down self compile data size by 100k and compile time by a few 
    seconds.
  - Added built in character and word cases propagated throughout all ILs.

* 2000-12-6
  - Added max stack size information to gc-summary.

* 2000-12-5
  - Added src/benchmark, which contains an SML program that benchmarks all of
    the SML compilers I have my hands on.  The script has lots of hardwired
    paths for now.

* 2000-12-4
  - Fixed bug in Posix.ProcEnv.environ, which did not work correctly in a saved
    world (the original environ was saved).  In fact, it did not work at all
    because the ML primitive expected a constant and the C was a nullary
    function. This caused a segfault with any program using
    Posix.ProcEnv.environ. 
  - Added MLton.ProcEnv.setenv, since there doesn't seem to be any setenv in
    the basis library.

* 2000-11-29
  - Changed backend so that it should no longer generate machine programs with
    void operands.
  - Added -detect-overflow and -safe flags.

* 2000-11-27 - 2000-11-28
  - Changes in many places to use List.revMap instead of List.map to cut down
    on allocation.

* 2000-11-21
  - Added MLton.Word.~ and MLton.Word8.~ to the MLton basis library structure.

* 2000-11-20
  - Fixed a bug in the CPS shrinker that could cause a compile-time failure.
    It was maintaining occurrence counts incorrectly.

* 2000-11-15
  - Fixed a (performance) bug in constant propagation that caused the hashing
        to be bad.
  - Improved translation to XML so that the match compiler isn't called on
        tuple or if expressions.  This should speed up the translation and
        make the output smaller.
  - Fixed a bug in the match compiler that caused it to not generate integer
        case statements.  This should speed up the mlyacc benchmark and the 
        MLton front end.

* 2000-11-9
  - Added IntInf_equal and IntInf_compare primitives.
  - Took out the automatic -keep c when compiling -g.

* 2000-11-8
  - Added a whole bunch of algebraic laws to the CPS shrinker, including
    some specifically targeted to IntInf primitives.

* 2000-11-3
  - Improved implementation of properties so that sets don't allocate.
  - Improved implementation of type homomorphism in type inference.  What
    was there before appears to have been a bug -- it didn't use the property
    on types.

* 2000-11-2
  - Fixed timers used with -v option to use user + sys time.

* 2000-10-27
  - Split the runtime basis library C files into many separate files so that
    only the needed code would be included by the linker.
  - Fixed several bugs in the front end grammar and elaborator that caused
    type specifications to be handled incorrectly.  The following three programs
    used to be handled incorrectly, but are now handled correctly.
      signature S = sig type t and u = int end (* reject *)
      signature S = sig type t = int and u = t end (* accept *)
      signature S = sig eqtype t and u = int end (* reject *)

* 2000-10-25
  - Changes to main.sml to run complete compiles with -native switch.

* 2000-10-24
  - Removed defunctorizer.

* 2000-10-20
  - Fixed bug in cps-tree.fun PrimExp.maySideEffect.  This bug could cause
    no operand failures in the backend.
  - Fixed bug in the runtime implementation of MLton.size.  The size for stack
    objects was using the used instead of reserved, and so was too low.

* 2000-10-19
  - Replaced automatically generated dependencies in src/runtime/Makefile with
    hand generated ones.  Took out make depend from src/Makefile.  makedepend
    was behaving really badly on RHAT 7.0.
  - Tweaked compiler to shorten width of C output lines to work around
        bug in RHAT 7.0 cpp which silently truncates (very) long lines.
  - Fixed bug in grammar that didn't allow "op" to occur in datatype and 
    exception bindings, causing the following to fail
        datatype t = op T
        exception op E = op Fail
  - Improved error messages in CM processor.  Fixed bug in CM Alias handling.

* 2000-10-18
  - Fixed two bugs in the gc that did comparisons with (s->limit - s->frontier),
    which of course doesn't work if frontier is beyond limit, since these are
    unsigned.  This could have caused segfaults, except that the mutator 
    checks the frontier upon return from the GC.

* 2000-10-17
  - Fixed bug in backend in the calculation of maxFrameSize.  It could be 
    wrong (low) in some situations.
  - Improved CPS inliner's estimate of function sizes.  The size of a function 
    now takes into account other inlined functions that the function calls. 
    This also changed the meaning of the size argument to the -inline switch.
    It now corresponds (roughly) to the product of the size of the function
    and the number of calls.  In general, it should be larger than before.
 
* 2000-10-13
  - Made some calls to Array.sub unsafe in the implementation of Array2.
  - Integrated Matthew's new x86 backend with floating point support.

* 2000-10-9
  - Fixed CM file processor so that MLton works if it is run from a different
    directory than the main CM file.

* 2000-10-4
  - Changed LimitCheck so it loops on the frontier > limit check.  This fixed
    a potential bug in threads caused when there is enough space available for
    a thread, t, before switching to another thread but not enough space when it
    resumes.  This could have caused a segfault.

* 2000-10-3
  - More rewrites of TextIO.StreamIO to improve speed.
  - Changed TextIO so that only TextIO.stdErr is unbuffered.
  - Changed TextIO so that FIFOs and sockets are buffered.

* 2000-10-2
  - Combined remove-unused-constructors, remove-unused-functions, and
    remove-unused-globals into a single pass that runs to fixed-point and
    produces results at least as good as running the previous three in (any)
    sequence. 

* 2000-9-29
  - Added GC_FIRST_CHECK, which does a gc at each limit check the first time it
    reached.
  - Reimplemented TextIO.StreamIO (from 2000-9-12) to use lists of strings
    instead of lists of characters so that the per char space overhead is small.

* 2000-9-21
  - Fixed bug in profiling labels in C code.  The label was always the basic 
    block label instead of the cps function label.
  - Added -b switch to mlprof to gather data at the basic block level.
  - Improved performance of TextIO.input1 by about 3X.

* 2000-9-15 - 2000-9-19
  - Added overflow exceptions to CPS and Machine ILs.

* 2000-9-12
  - Fixed TextIO.scanStream.  It was very broken.
  - Added TextIO.{getInstream,mkInstream,setInstream}
          TextIO.StreamIO.{canInput,closeIn,endOfStream,input1,input,inputAll,
                           inputLine,inputN}

* 2000-9-11
  - Fixed Real_qequal in mlton-lib.h.  It was missing a paren that caused
    code using it to not even compile.  It was also semantically incorrect.
  - Noted that Real_{equal,lt,le,gt,ge} may not follow basis library spec, since 
    ANSI does not require IEEE compliance, and hence these could return wrong
    results when nans are involved.

--------------------------------------------------------------------------------

Here are the changes from the 20000712 version to the 20000906 version.

    Version 20000906 is mostly a bugfix release over 20000712.  The other major
    changes are that mllex and mlyacc are now included and
    that mlton can now process a limited subset of CM files as input.

* 2000-9-6
  - Fixed Socket_listen in mlton-lib.c so that it closes the socket if the 
        bind, listen, or getsockname fails.  This could have caused a file
        descriptor leak.

* 2000-9-5
  - Added -static commandline switch.
  - Changed default max heap size to .85 RAM from .95 RAM.
  - Added PackRealLittle structure to basis library.

* 2000-8-25
  - Added cases on integers to ILs (instead of using sequences of tests) so that
    backend can emit more efficient test (jump table, binary tree, ...).

* 2000-8-24
  - Fixed bug in gc.c.  dfsInitializeStack would smummap a NULL pointer whenver
    toSpace was NULL.  This could gause MLton.size to segfault.
  - Fixed bug in Popt that caused -k to fail with no keeps.

* 2000-8-22 - 2000-8-23
  - Ported mllex and mlyacc from SML/NJ

* 2000-8-20 - 2000-8-21
  - Added ability to us a .cm file as input to MLton.

* 2000-8-16
  - Ported mlprof to SML.
  - Fixed bug in library/basic/assert.sml that caused asserts to be run even
    when MLton.debug = false.

* 2000-8-15
  - Fixed bug in backend -- computation of maxFrameSize was wrong.  It didn't
    count slots in frames that didn't make nontail calls.  This could lead to
    the stack being overwritten because a stack limit check didn't guarantee 
    enough space, and lead to a seg fault.
  - Fixed bug in gc.c newThreadOfSize.  If the thread allocation caused a gc,
    then the stack wasn't forwarded, leading to a seg fault.  The solution was
    to ensure enough memory all at once, and then fill in both objects.

* 2000-8-14
  - Changed limit checks so that checks < 512 bytes are replaced by a check for
    0.  The runtime also moves the limit down by 512.  This is done so that the
    common case, a small limit check, has less code and is faster.
  - Fixed bug in cps/cps-tree.fun Program.hasPrim returned true for any program
    that had *any* primapp, not just programs satisfying the predicate.  This
    caused cps/once.fun to be overly conservative, since it thought that every
    program used continuations.

* 2000-8-10
  - Fixed bug in CPS typechecker.  It didn't enforce that handlers should be
    defined before any reference to them -- including implicit references in 
    HandlerPops.  This caused an evil bug in the liveness analysis where a 
    variable that was only live in the handler was missed in a continuation
    because the liveness for the handler wasn't computed yet.
  - Limited the size for moving up limit checks for arrays whose size is known
    at compile time to avoid huge limit checks getting moved into loops.
  - added -indent, -kp, -show-types switches.
  - Put optimization in CPS IL suggested by Neal Glew.  It determines for each
    toplevel function if it can raise an exception to its caller.  Also, it
    removes HanderPush and HandlerPop for handlers that are not on top of the 
    stack for any nontail call.

* 2000-8-8
  - Changed register allocator so that continuation formals can be allocated in
    pseudo registers -- they aren't necessarily forced to the stack.

* 2000-8-3
  - Fixed bug in constant folding.  
        Word8.>> had been used to implement Word8.~>>.
  - Fixed bug in allocate registers that was not forcing the size argument to
    Primitive.Array.array to be a stack slot.  This could cause problems if
    there was a thread switch in the limit check, since upon return the size
    pseudo register would have a bogus value.

* 2000-8-1
  - Turned back on Xml simplification after monomorphisation.

* 2000-7-31
  - Fixed bug in MLton.Itimer.set that caused the time to be doubled.
  - Fixed bug in MLton.Thread that made it look like asynchronous exceptions
    were allowed by throw'ing an exception raising thunk to an interrupted
    thread obtained via a signal handler.  Attempting asynchronous exceptions
    will now cause process death, with a helpful error message.

* 2000-7-27
  - Updated docs to include structure World: MLTON_WORLD in MLton structure.
  - Added toplevel signatures MLTON_{CONT, ..., WORLD} to basis library.
  - Fixed broken link in docs to CM in cmcat section.

* 2000-7-26
  - Eliminated GC_switchToThread and Thread_switchTo1, since the inlined
    version Thread_switchTo is all that's needed, and Matt's X86 backend 
    now handles it.
  - Added MLton.Signal.vtalrm, needed for 
    Itimer.Set{which = Itimer.Virtual, ...}

* 2000-7-25
  Added MLton.Socket.shutdownWrite.

* 2000-7-21
  Updated mlton-lib.c MLton_bug with new email (MLton@sourcelight.com).

* 2000-7-19
  Fixed Posix.Process.kill to check for errors.

* 2000-7-18
  Fixed the following Posix.ProcEnv functions to check for errors:
    setgid, setpgid, setsid, setuid.
  Fixed doc/examples/callcc.sml.

--------------------------------------------------------------------------------

Here are the changes from the 1999-7-12 to the 20000712 version.

* 2000-6-10 - 2000-7-12
  Too many changes to count: bug fixes, new basis library modules,
        optimizer improvements.
* 2000-6-30
  Fixed bug in monomorphiser that caused programs with non-value
  carrying exception declarations in polymorphic functions to have a
  compile-time error because of a duplicate label.  The problem was
  that the exception constructor wasn't duplicated.
* 2000-5-22 - 2000-6-10
  Finished the changes for the new Cps IL.
* 2000-1-1
  Fixed some errors in the basis library.
        Real.copySign
        Posix.FileSys.fpathconf
        Posix.IO.{lseek, getlk, setlk, setlkw}
        Posix.ProcEnv.setpgid
        Posix.TTY.getattr
        System.FileSys.realPath
* 1999-12-22
  Fixed bug in src/closure-convert/abstract-value.fun that caused a
  compiler failure whenever a program had a vector where the element
  type contained an ->.
* 1999-12-10
  - Changed dead code elimination in core-ml/dead-code.fun so that
    wildcard declarations (val _ = ...) in the basis are kept.
    Changed places in the basis library to take advantage of this
  - Added setTopLevelHander primitive so that the basis library code
    can define the toplevel handler.
  - Changed basis-library/misc/suffix.sml to call OS.Process.exit.
    Took out Halt transfer from Cps, since the program never should
    reach it.
  - Cleaned up basis-library/system/{process.sml, unix.sml} to use
    the new signal handling stuff.
* 1999-11-28 - 1999-12-20
  Added support for threads and cleaned up signal handling.
  This involved a number of changes.
  - The stack is now allocated as just another kind of heap object.
  - Limit checks are inserted at all loop headers, whether or not there
    is any allocation.  This is to ensure that the signal handler
    always has a chance to get called.
  - The register allocator puts more variables in stack slots.  The new
    rule is that a variable goes in a stack slot if it is ever live
    across a nontail call, in a handler, or (this is the new part)
    across a limit check.
  - Arguments are passed on the stack, with the convention determined by 
    argument types.
  - The "locals" array of pointers that was copied to/from for GC is now 
    gone, because no registers (in particular no pointer valued
    registers) can be live at a limit check point.
* 1999-11-21
  - Runtime system
    o Fixed a bug introduced by the signal code
        (presumably on 1999-8-9) that caused a gc to *not* be performed when
        doing a save world.  This caused the heaps created by save world to
        be the same size as the heap -- not the live data.  This was quite
        bad. 
    o Cleaned up the Makefile.  Add make depend.
    o Added max gc pause to gc-summary info.
    o Move heap translation variables that had been file statics into
        the GC_state.
  - Made structure Position available at toplevel.
  - Basis Library
    o Added MLton.loadWorld
  - Added Primitive.usesCallcc
  - Added Primitive.safe
  - Removed special size functions from cps/save-world -- they are no
    longer necessary since size doesn't do a gc.
  - Fixed another (sigh) bug in cps/simplify-types.fun that could
    cause it to not terminate.
* 1999-11-16
  - Cleaned up backend/machine.fun a bit so that it spits out macros
    for allocation of objects and bumping of frontier.  Added macros
    MLTON_object and MLTON_incFrontier to include/mlton-lib.h.
  - Fixed a bug in backend/limit-check.fun that caused loops to not be 
    detected if they were only reached by a case branch.  This could 
    cause there to be loop that allocates with no limit check.
    Needless to say, this could cause a segfault if the loop ran for
    long enough.
* 1999-10-18
  Added basis library function Array2.copy.
* 1999-8-15
  Turned off globalization of ref cells
  (closure-convert/globalize.fun) because it interacts badly with
  serialization.
* 1999-8-13
  Fixed bug in mlton-lib.h in MLTON_allocArrayNoPointers that was
  triggered when bytesPerElt == 0.  The problem was that it wasn't
  reserving space for the forwarding pointer.  This could cause a seg
  fault. 
* 1999-8-8 and 1999-8-9
  Added support for signal handling.
* 1999-8-7
  Fixed bugs in Array.tabulate (and other tabulate variants) caused if
  the function argument used callcc.
* 1999-8-1
  Added serialization, which was mostly code in src/runtime/gc.c.
  GC_serialize converts an object to a Word8Vector.vector.
  GC_deserialize undoes the conversion.
  (de)Serialization should work for all objects except for functions,
  because I haven't yet added the support in the flow analysis.
* 1999-7-31
  - Cleaned up the GC.  Changed headers, by stealing a bit from the
    number of non pointers and making it a mark bit (used in GC_size).
  - Rewrote GC_size so that it runs in time proportional to the number 
    of pointers in the object.  It does a depth-first-search now,
    using toSpace to hold the stack.
* 1999-7-30
  - Fixed bug in SUBSTRING.  getc had the wrong type.  This bug wasn't
    noticed because MLton doesn't do enough type checking.
  - Fixed bug (seg fault) caused when a GC immediately followed a throw.
* 1999-7-29
  Fixed bug in Date.fmt (basis-library/system/date.sml).  It was not
  setting Tm.buf, and hence the time was always 0 unless there had
  been a previous call to setTmBuf.
* 1999-7-28
  - Fixed bugs in Posix.IO.FLock.{getlk,setlk,setlkw}, which would
    cause compilation to fail because FLock.toInt was defined as the C 
    castInt, which no longer exists.  Instead, expand FLock.toInt to
    MLTON_pointerToInt, which was added to include/mlton-lib.h.
  - Changed Posix.Primitive.Flock to Posix.Primitive.FLock.
  - Added MLTON_chown, MLTON_ftruncate to include/mlton-posix.h.  They were
    missing.  This would cause compilation of any program using
    Posix.FileSys.{chown,ftruncate} to fail.  Also made it so all of the
    primitives in basis-library/posix/primitive.sml use MLTON_ versions
    of functions, even if a wrapper is unnecessary.
* 1999-7-25
  Added some other missing signature definitions to toplevel.
* 1999-7-24
  Added missing OS_* signature definitions to 
  basis-library/top-level/top-level.sml.
* 1999-7-19
  Fixed bug in basis-library/arrays-and-vectors/mono-array.sml.  Used
  :> instead of : so that the monomorphic array types are abstract.

--------------------------------------------------------------------------------

Here are the changes from the 1999-3-19 version to the 1999-7-12 version.

* 1999-7-12
  Changed src/backend/machine.fun so that the 'pointer locals' array is
  only as large as neccessary in order to copy all pointer-valued
  locals, not as large as the number of pointer-valued locals.
* 1999-7-11
  Rewrote src/backend/allocate-registers.fun so that it does a better
  job of sharing "registers" (i.e. C local variables) and stack slots.
  This should cut down on the amount of copying that has to happen
  before and after a gc.  It should also cut down on the size of stack 
  slots.
* 1999-7-10
  Fixed a bug in src/backend/parallel-move.fun that should have been
  triggered on most any parallel move.  I guess parallel moves almost
  never happened due to the old register allocation strategy -- but, 
  with the new one (see note for 1999-7-12) parallel moves will be 
  frequent.
* 1999-6-27
  Fixed src/main.sml so that when compiling -p, the .c file is compiled 
        -g and the .o is linked -p. 
  In bakend/machine.fun, added profiling comments before chunkswitches 
        and put in an optimization to avoid printing repeated profiling
        comments.  Also, profiling comments are only output when
        compiling -p.
* 1999-6-17
  Changed -i to -inline, -f to -flatten, -np to -no-polyvariance, 
        -u to -unsafe.
  Added -i, -I, -l, -L flags for includes and libraries.
  Updated documentation for these options and for ffi.
* 1999-6-16
  Hardwired version number in src/control/control.sml.  As it stood,
  the version number was computed when MLton was built after someone
  downloaded it, which was clearly wrong.
* 1999-6-16
  Fixed undefined variable time in GC_done in src/runtime/gc.c.
* 1999-6-8
  in include/mlton-lib.h, 
     removed #include <huge_val.h>
     added #include <math.h>
     and deleted all of the function signatures I had copied from math.h
  Changed Real.{minNormalPos, minPos, maxFinite} so that they are
        computed in real.sml instead of appearing as constants in the C.
* 1999-6-7
  IntInf.pow added to basis library.
* 1999-6-4
  bin/mlton changed to use .arch-n-opsys if it exists. 
* 1999-6-3
  src/Makefile changed to use sml-cm instead of sml
* 1999-5-10
  Patch to src/atoms/small-int-inf.fun to work around a bug in the SML/NJ 
  implementation of bignums.  This bug was causing some hex bignum
  constants to be lexed incorrectly.
* 1999-4-15
  Comments emitted in C code for profiling.  The comments identify the 
  Cps function responsible for each C statement.
* 1999-4-15
  callcc and throw added.
* 1999-4-15
  Bug in src/cps/simplify-types fixed.  The bug caused nontermination
   whenever there was a circular datatype with a vector on the rhs.
   E.g.  datatype t = T of t vector

--------------------------------------------------------------------------------

Here are the changes from the 1998-8-26 version to the 1999-3-19 version.

* Compile time and code size have decreased.
* Runtime performance of executables has improved.
* Large programs can now be compiled.
* MLton is self hosting.
* The basis library is mostly complete and many bugs have been fixed.
* The monomorphiser (-m) is no longer available.
* The heap and stack are automatically resized.
* There are now facilities for heap checkpointing (MLton.saveWorld)
  and object size computation (MLton.size).
* MLton uses the GNU multiprecision library to provide a fast
  implemenation of IntInf. 
