cbfalconer

I believe gcc runs on at least HPUX, Windows, Solaris, Linux, AIX.
Quite likely some, if not all, of the other named ones.

Here are a few of the systems it runs on, according to "info gcc":

_Machine Dependent Options_
*Note Hardware Models and Configurations: Submodel Options.

_M680x0 Options_
_M68hc1x Options_
_VAX Options_
_SPARC Options_
_Convex Options_
_AMD29K Options_
_ARM Options_
_MN10200 Options_
_MN10300 Options_
_M32R/D Options_
_M88K Options_
_RS/6000 and PowerPC Options_
_RT Options_
_MIPS Options_
_i386 and x86-64 Options_
_HPPA Options_
_Intel 960 Options_
_DEC Alpha Options_
_DEC Alpha/VMS Options_
_Clipper Options_
_H8/300 Options_
_SH Options_
_System V Options_
_ARC Options_
_TMS320C3x/C4x Options_
_V850 Options_
_NS32K Options_
_AVR Options_
_MCore Options_
_MMIX Options_
_IA-64 Options_
_D30V Options_
_S/390 and zSeries Options_
_CRIS Options_
_PDP-11 Options_
_Xstormy16 Options_
_Xtensa Options_

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>