Watcom C/C++ compiler
|Original author(s)||Watcom, Sybase,
|Initial release||January 8, 2003|
|Stable release||1.9 / June 2, 2010|
|Written in||C, C++|
|Size||66 to 84 Mb|
|Type||Integrated development environment|
|License||Sybase Open Watcom Public License version 1.0|
Though no longer sold commercially by Sybase, the Watcom C/C++ compiler and the Watcom Fortran compiler have been made available as a gratis and questionably open source Open Watcom package with the assistance of SciTech Software.
The Open Source Initiative has approved the license while Debian, Fedora and the Free Software Foundation have rejected it. The code is portable and, like many other open source compiler projects such as GCC or LCC the compiler backend (code generator) is retargetable.
The compiler can be operated from, and generate executable code for, the DOS (MS-DOS, FreeDOS), OS/2, Windows, Linux operating systems. It also supports NLM targets for Novell NetWare. There is ongoing work to extend the targeting to Linux and modern BSD (e.g., FreeBSD) operating systems, running on x86, PowerPC, and other processors.
The Open Watcom C/C++ version 1.4 release on December 2005 introduced Linux x86 as an experimental target, supported from NT or OS/2 host platforms. There is code for an abandoned QNX version, but libraries necessary for it to be compiled could not be released as open source.
Stable version 1.9 was released in June 2010.
In the mid-1990s some of the most technically ambitious MS-DOS computer games such as Doom, Descent, Duke Nukem 3D, and Rise of the Triad were built using Watcom C/C++, some such as ROTT using the DOS/4GW protected mode extender with the Watcom compiler.
Compatibility with other compilers
Open Watcom's syntax supports many conventions introduced by other compilers, such as Microsoft's and Borland's, including differing conventions regarding (for instance) the number of leading underscores on the "asm" tag. Code written specifically for another compiler rather than standard-compliant C or C++ will often compile with the Watcom compiler.
The Open Watcom Wiki has a comprehensive history.
|1984||Waterloo C for S/370|
|1985||Work on current code generator codebase started|
|1988||Watcom C 6.0||
|1989||Watcom C 7.0|
|1989||Watcom C 7.0/386|
|1990||Watcom C 8.0|
|1990||Watcom C 8.0/386|
|1991||Watcom C 8.5|
|1991||Watcom C 8.5/386|
|1992||Watcom C 9.0|
|1992||Watcom C 9.0/386||
|Watcom C 9.01/386||
|1993||Watcom C/C++ 9.5|
|1993||Watcom C/C++ 9.5/386|
|1994||Watcom C/C++ 10.0|
|1995||Watcom C/C++ 10.5|
|1996||Watcom C/C++ 10.6|
|1997||Watcom C/C++ 11.0|
|1998||Watcom C/C++ 11.0B|
|1999||Sybase issues end-of-life notice for Watcom C/C++ 11.0|
|2000||Sybase announces open sourcing of Watcom tools|
|2001-09-27||Watcom C/C++ 11.0c Beta|
|2002-12-21||Watcom C/C++ 11.0c|
|2003-01-28||Open Watcom 1.0|
|2003-08-12||Open Watcom 1.1|
|2004-01-07||Open Watcom 1.2|
|2004-08-03||Open Watcom 1.3|
|2005-12-14||Open Watcom 1.4|
|2006-04-26||Open Watcom 1.5|
|2006-12-15||Open Watcom 1.6|
|2007-08-18||Open Watcom 1.7|
|2007-10-23||Open Watcom 1.7a|
|2009-02-21||Open Watcom 1.8|
|2010-06-02||Open Watcom 1.9||Current Version|
The GNU project considers the Open Watcom license "nonfree" because "It requires you to publish the source code publicly whenever you “Deploy” the covered software, and “Deploy” is defined to include many kinds of private use."
- Installing Open Watcom on Linux - Open Watcom. OpenWatcom.org wiki.
- "Latest Release (June 2010) - Open Watcom". OpenWatcom.org wiki.
- History - Open Watcom. OpenWatcom.com wiki.
-  "RotT was written in Watcom C++ v10.0 with the Rational Systems DOS/4GW extender."
- "Open Watcom V2 Fork".
- "Open Watcom V2 Fork Project on GitHub".
- "pcdosasm.zip archive". 2010-07-27. Retrieved 2014-02-10.
Modified Open Watcom C/C++ DOS 16-bit ..\STARTUP\DOS\CSTRT086.ASM code
- Free Software Foundation. "Various Licenses and Comments about Them". GNU Operating System. Retrieved Dec 23, 2014.