C [http://cm.bell-labs.com/cm/cs/cbook/index.html] is a programming language 
found first
[http://cm.bell-labs.com/cm/cs/who/dmr/chist.html]
on Unix systems but now found on many platforms.
The [FSF]'s [gcc] compiler is a quite popular C compiler found on many
platforms and operating systems.

Also, most Unix systems have vendor supported compilers.  They are often unbundled products these days. Sun is one of the vendors who have this type of product.

On [Microsoft Windows] there are many options,
including
   * the commercially available Visual C++ from [Microsoft],
   * [C++Builder] from [Borland],
   * the [Cygwin] C compiler (a version of [gcc]; for some strange reason it cannot be used to compile the [Tcl] source code itself - but Cygwin comes with its own version of Tcl at least),
the Mingw C compiler [http://www.mingw.org/] (another version of [gcc] for Windows with slightly different goals),
CodeWarrior [http://www.metrowerks.com/MW/Develop/Desktop/Windows/default.htm],
Digital Mars C [http://www.digitalmars.com/], which was once Zortech C and later became Symantec C,
LCC-Win32 [http://www.cs.virginia.edu/%7Elcc-win32/] [[Can that compile Tcl itself?]],
etc.

The number of C compilers available on [MacOS] is more limited.  There is the commercially available CodeWarrior by Metrowerks [http://www.metrowerks.com] for MacOS Classic and [MacOS X], Apple's MPW for MacOS Classic (a free download these days), and only under [MacOS X], there is [gcc], either used stand-alone or with Apple's free ProjectBuilder IDE.

----
[[
[C code generators] | [C Language]
]]
----
[[
[Category Language]
]]