A portable, freeware Super Nintendo emulator. Written primarily by Gary Henderson (correct me if I'm wrong).

It runs under the X window system, svgalib, and it supports Voodo 3dfx cards.

It works pretty well, although it can't beat the Real Thing (and it slurps up almost all your CPU cycles).

It currently emulates:

• The 65c816 main CPU.
• The Sony SPC700 sound CPU.
• SNES variable length cycles.
• 8 channel DMA and H-DMA (raster effects).
• All background modes, 0 to 7.
• Sound DSP, with eight 16-bit stereo channels, compressed samples, hardware attack-decay-sustain-release volume processing, echo, pitch modulation and digital FIR sound filter.
• 8x8, 16x8 and 16x16 tile sizes, flipped in either direction.
• 32x32, 32x64, 64x32 and 64x64 screen tile sizes.
• H-IRQ, V-IRQ and NMI.
• Mode 7 screen rotation, scaling and screen flipping.
• Vertical offset-per-tile in modes 2, and 4.
• 256x224, 256x239, 512x224, 512x239, 512x448 and 512x478 SNES screen resolutions.
• Sub-screen and fixed colour transparency effects.
• Mosaic effect.
• Single and dual graphic clip windows, with all four logic combination modes.
• Colour effects only inside a window.
• 128 8x8, 16x16, 32x32 or 64x64 sprites, flipped in either direction.
• SNES palette changes during frame (15/16-bit internal rendering only).
• Direct colour mode - uses tile and palette-group data directly as RGB value.
• Super FX, a 21/10MHz RISC CPU found in the cartridge of several games.
• SNES mouse.
• SuperScope (light gun) emulated using computer mouse.
• Multi-player 5 - allowing up to five people to play games simultaneously on games that support that many players.
• Game-Genie, Action Replay and Gold Finger cheat codes.
• Multiple ROM image formats, with or without a 512 byte copier header.
• Single or split images, compressed using gzip, and interleaved in one of two ways.
• Auto S-RAM (battery backed RAM) loading and saving.
• Freeze-game support, now portable between different Snes9x ports.
• Interpolated sound.

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!