Snes9x may very well be the single most portable emulator in the history of emulation. At one time or another, it has run on DOS, Windows 9x, Windows NT and 2000/XP/2003, OS/2, Linux, FreeBSD, NetBSD, OpenBSD, Solaris, AIX, HP-UX, Mac OS, Mac OS X, NeXTSTEP, IRIX and even BeOS - but more than this, there was even a port to the Nintendo 64! Ports to the Playstation and Playstation 2 existed, too.
Some of these ports weren't even intentional, like the AIX one - the source code just happened to compile on AIX with minor tweaks. Others, like the Solaris and IRIX ports, had full support status. There were even documents on the Snes9x website detailing exactly how to install and run it on a Sun Ultra 60, and on an SGI Fuel! In fact, when the 2xSaI and Super Eagle image scaling algorithms were added, the system requirements actually recommended a SPARC CPU. Now, this is largely because, at the time, the Pentium 2/300 was the most current x86, while a 400MHz UltraSPARC existed, but it is somewhat telling!