Historical Versions Of MASM
Microsoft introduced the Microsoft Macro Assembler in 1981 and it has been in continuous production ever since being upgraded on a needs basis with operating system and hardware changes, a period of over 30 years. Over its many years of production it has become the defacto industrial standard for x86 assembler in Microsoft operating systems from MS-DOS to current versions of Microsoft Windows.

It is characteristically an industrial software development tool maintained by a major operating system vendor as a component of their own development environment and it has never been compromised to become a user friendly tool at the expense of its capacity. It generally requires experienced assembler programmers who are both familiar with Intel mnemonics and x86 architecture as it is implemented in a range of 32 bit capable Windows operating system.

Versions 7.0 and upwards are components of the Microsoft Visual C++ development environment and have also been made available in a number of device development kits for successive versions of Microsoft Windows. The current versions of ML.EXE are 9, 10 and 11 depending on the operating system version that it is used with.

The following reference material in this page is for versions prior to version 7.0 and is taken directly from the file dates and copyright text in the original Microsoft binary files supplied since 1981. The list is not exhaustive but it is near complete with actual binary files dating back to 1984. Earlier versions of the Microsoft Macro Assembler were named MASM.EXE and the Microsoft Assembler is still generally referred to as MASM even though the file name for the assembler was changed to ML.EXE in 1991 with the release of MASM version 6.0.

The Visual C++ 6.0 Processor Pack
The Visual C++ 6.0 Processor Pack was released by Microsoft in 2000 to integrate the Microsoft Macro Assembler into the main Microsoft development environment. Its EULA requires the user to have a valid licence to Visual C++ 6.0 and also afforded licence holder the right to copy and redistribute the processor pack to other licence holders of Visual C++ 6.0.
vcpp5.exe 1,180,896 bytes    25/9/2000

ML.EXE Version 6.15
ML.EXE    385,072 bytes      3/16/2000
Microsoft (R) Macro Assembler Version 6.15.8803
Copyright (C) Microsoft Corp 1981-2000.  All rights reserved.

MASM 6.14 patch for ML.EXE 6.11
Microsoft released the 6.14 patch in 1999 to upgrade ML.EXE from an MS-DOS MZ executable file into a console mode 32 bit Portable Executable binary file.
PATCH.EXE  189,440 bytes     4/6/1999

ML.EXE Version 6.14
ML.EXE     372,736 bytes     3/29/1999
Microsoft (R) Macro Assembler Version 6.14.8444
Copyright (C) Microsoft Corp 1981-1997.  All rights reserved.

NOTE that the earlier patches for versions 6.12 and 6.13 have not been addressed here.
Unreferenced ML.EXE versions
In the interim period between the last commercial release of MASM 6.11 and the introduction of patches that upgraded this version, Microsoft supplied a number of variant versions of ML.EXE to MSDN subscribers in various forms in device development kits (DDK) and software development kits (SDK).

MASM Version 6.11
In MASM version 6.11 the assembler is ML.EXE. MASM.EXE is a compatibility driver for users of earlier versions of MASM.
MASM.EXE    49,152  bytes    8/19/1993
Microsoft (R) MASM Compatibility Driver Version 6.11
Copyright (C) Microsoft Corp 1993.  All rights reserved.
ML.EXE      388,608 bytes    9/24/1993
Microsoft (R) Macro Assembler Version 6.11
Copyright (C) Microsoft Corp 1981-1993.  All rights reserved.

MASM Version 6.0
In MASM version 6.0 the assembler is ML.EXE. MASM.EXE is a compatibility driver for users of earlier versions of MASM.
MASM.EXE    21,025  bytes    4/2/1991
Microsoft (R) MASM Compatibility Driver
Copyright (C) Microsoft Corp 1991.  All rights reserved.
ML.EXE      244,690 bytes    4/3/1991
Microsoft (R) Macro Assembler Version 6.00
Copyright (C) Microsoft Corp 1981-1991.  All rights reserved.

MASM Version 5.1
In MASM version 5.1 the assembler is MASM.EXE.
MASM.EXE    110,703 bytes    2/1/1988
Microsoft (R) Macro Assembler Version 5.10
Copyright (C) Microsoft Corp 1981, 1988.  All rights reserved.

MASM Version 5.0
In MASM version 5.0 the assembler is MASM.EXE.
MASM.EXE    103,175 bytes    7/31/1987
Microsoft (R) Macro Assembler Version 5.00
Copyright (C) Microsoft Corp 1981-1985, 1987.  All rights reserved.

MASM Version 3.0
In MASM version 3.0 the assembler is MASM.EXE.
MASM.EXE    77,362 bytes     11/21/1984
Microsoft MACRO Assembler  Version 3.00
(C)Copyright Microsoft Corp 1981, 1983, 1984