Watcom C/C++#History

In 2000, Sybase, who owned Watcom International Corporation halted the commercial sale of the Watcom C/C++ and Fortran compilers. In 2003, SciTech Software Inc, a customer of Sybase, negotiated wth Sybase, to have the code for the compilers released as an open source project under a new name, Open Watcom.{{cite web |url=http://www.openwatcom.com/about.php |archive-date=April 29, 2016 |archive-url=https://web.archive.org/web/20160429054902/http://www.openwatcom.com/about.php |title=Open Watcom dot org About us |publisher=OpenWatcom.org wiki |url-status=dead}} The Watcom C/C++ compiler and the Watcom Fortran compiler were made available free of charge as the Open Watcom package.

The last stable version endorsed by the original openwatcom.org team was 1.9, released in June 2010.{{cite web |url=https://www.openwatcom.org/index.php/Main_Page |archive-date=January 18, 2015 |archive-url=https://web.archive.org/web/20150118220613/http://www.openwatcom.org/index.php/Main_Page |title=Latest Release (June 2010) - Open Watcom |publisher=OpenWatcom.org wiki |url-status=dead}}{{cite web |title=C Compiler Release Changes |url=https://www.openwatcom.org/index.php/C_Compilers_Release_Changes |website=Open Watcom |archive-url=https://web.archive.org/web/20150203100434/http://www.openwatcom.org/index.php/C_Compilers_Release_Changes |archive-date=February 3, 2015 |date=March 9, 2010 |url-status=dead}}

A community-based forked version 2.0 (with continuous updates under the same version moniker) was released after the original codebase was seemingly no longer developed by the original team. It includes miscellaneous bugfixes, supports 64-bit hosts (Windows and Linux), built-in text editor, 2-phase build system, and has a DOS version that supports long filenames (LFN).[https://open-watcom.github.io Open Watcom v2 Fork]

The Open Watcom Wiki has a comprehensive history.

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{{Main|Sybase Open Watcom Public License}}

The Open Source Initiative has approved the license as open source, but Debian, Fedora and the Free Software Foundation have rejected it 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."{{cite web|last1=Free Software Foundation|title=Various Licenses and Comments about Them|url=https://www.gnu.org/licenses/license-list.html#Watcom|website=GNU Operating System|access-date=Dec 23, 2014}}

The compiler can be operated from, and generate executable code for, the DOS, OS/2, Windows, Linux operating systems. It also supports NLM targets for Novell NetWare. There is ongoing work to extend the targeting to Linux[https://web.archive.org/web/20150506003855/http://openwatcom.org/index.php/Installing_Open_Watcom_on_Linux Installing Open Watcom on Linux - Open Watcom]. OpenWatcom.org wiki. and modern BSD (e.g., FreeBSD) operating systems, running on x86, PowerPC, and other processors.

The code is portable and, like many other open source compiler projects such as GCC or LCC the compiler backend (code generator) is retargetable.

In the mid-1990s some of the most technically ambitious DOS computer games such as Doom,[https://web.archive.org/web/20210324032810/http://wiki.openwatcom.org/index.php/History History - Open Watcom]. OpenWatcom.com wiki. Descent, Duke Nukem 3D, Rise of the Triad,{{cite web|url=http://legacy.3drealms.com/faq/rottfaq30.txt|title=RotT was written in Watcom C++ v10.0 with the Rational Systems DOS/4GW extender}} and Tomb Raider were built using Watcom C/C++ using the DOS/4GW protected mode extender with the Watcom compiler.

It was used to port the game Retro City Rampage to DOS in 2015.{{ cite web | url = https://www.gamedeveloper.com/programming/how-5-years-of-burning-ambition-brought-i-retro-city-rampage-i-to-dos |title=How 5 years of burning ambition brought Retro City Rampage to DOS |date=10 July 2015 |publisher=Gamasutra }}

It was used by VirtualBox to compile the BIOS.{{Cite web|url=https://www.virtualbox.org/ticket/12011|title=#12011 (Compiling BIOS requires Open Watcom compiler)– Oracle VM VirtualBox|website=www.virtualbox.org|access-date=2017-06-17}}

Current development for FreeDOS requires that all C source code must be compilable by Open Watcom C.{{cite web |title=FreeDOS Spec |url=http://wiki.freedos.org/wiki/index.php/FreeDOS_Spec |publisher=FreeDOS |archive-url=https://web.archive.org/web/20190501051417/http://wiki.freedos.org/wiki/index.php/FreeDOS_Spec |archive-date=May 1, 2019 |url-status=live}}

Open Watcom is the recommended compiler for application and driver development for the OS/2-based ArcaOS operating system.{{cite web|url=https://www.arcanoae.com/wiki/information-for-developers/|title=Information for developers|website=arcanoae.com|access-date=2020-09-06}}

Open Watcom's syntax supports many conventions{{Which|date=October 2018}} introduced by other compilers, such as Microsoft's and Borland's, including differing conventions{{Which|date=October 2018}} 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 compiler supports C89/C90 standards by default.

Open Watcom supports partial compatibility with the C99 standard. It implements the most commonly used parts of the standard. However, they are enabled only through the undocumented command-line switch "-za99". Three C99 features have been bundled as C90 Extension since pre-v1.0: C++ style comments (//), flexible array members, trailing comma allowed in enum declaration.{{cite web|url=https://wiki.openwatcom.org/index.php/C99_Compliance |title=C99 compliance in Open Watcom |archive-url=https://web.archive.org/web/20210329095056/http://wiki.openwatcom.org/index.php/C99_Compliance |archive-date=2021-03-29}}

The compiler currently doesn't support any new{{When|date=October 2018}} major C11 features, though the C library does include "Safe C" functions. It is specified in ISO/IEC TR 24731-1[https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1225.pdf ISO/IEC TR 24731-1; Extension to the C Library, Part 1: Bounds-checking interfaces.][https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1969.htm WG14 N1969 — "Updated Field Experience With Annex K — Bounds Checking Interfaces", Carlos O'Donell, Martin Sebor] and known as "Bounds-checking interfaces (Annex K)" in C11. Some function name examples are strcpy_s(), memcpy_s(), printf_s().{{cite web|url=http://wiki.openwatcom.org/index.php/Safer_C_Library |title=Open Watcom Safer C Library |access-date=2020-11-30}} This library was released along with Open Watcom 1.5 in April 2006.

In a February 1989 overview of optimizing C compilers, BYTE praised Watcom C 6.5's "unmatched execution speed" and noted that it was the most ANSI C-compliant. The magazine advised, "If speed is absolutely critical and OS/2 compatibility isn't, choose Watcom".{{Cite magazine |last1=Apiki |first1=Steven |last2=Udell |first2=Jon |date=February 1989 |title=Smoothing Out C |url=https://archive.org/details/eu_BYTE-1989-02_OCR/page/n225/mode/1up?view=theater |access-date=2024-10-08 |magazine=BYTE |pages=170–186}}

• Open Watcom Assembler

{{Reflist}}

• [https://web.archive.org/web/19970712221411/http://www.byte.com/art/9410/sec12/art5.htm Watcom C/C++ Gets a New Face] – review in October 1994 BYTE magazine
• [https://web.archive.org/web/20220304045500/http://www.azillionmonkeys.com/qed/watfaq.shtml The WATCOM C/C++ Programmer's FAQ]

;Current

• [https://github.com/open-watcom/open-watcom-v2 Open Watcom 2.0 fork] – GitHub

;Archives

• [https://github.com/open-watcom/open-watcom-1.9 Open Watcom 1.9] – GitHub
• {{Official website|openwatcom.org|Open Watcom}} 1.9 – ({{webarchive |url=https://web.archive.org/web/20150317091931/http://www.openwatcom.org/index.php/Main_Page |date=March 17, 2015 }})
• Sybase Watcom C/C++ version 11.0 – ({{webarchive |url=https://web.archive.org/web/19991013131936/http://sybase.com/products/languages/watccpl.html |date=October 13, 1999 }})

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Category:C (programming language) compilers

Category:C++ compilers

Category:Formerly proprietary software

Category:2003 software