Fuse (the Free Unix Spectrum Emulator) was originally, and somewhat unsurprisingly, a Spectrum emulator for Unix. However, it has now also been ported to Mac OS X, which may or may not count as a Unix variant depending on your advocacy position.

What features does it have?

- Working 16K, 48K, 128K, +2, +2A, +3, +3e, SE, TC2048, TC2068, TS2068, Pentagon 128 and Scorpion ZS 256 emulation, running at true Speccy speed.
- Support for loading from .tzx files.
- Sound
- Kempston joystick emulation.
- Emulation of the various printers you could attach to the Spectrum.
- Support for the RZX input recording file format, including 'competition mode'.
- Emulation of the DivIDE, Interface I, Kempston mouse, Spectrum +3e, ZXATASP and ZXCF interfaces.
- Advanced MAME graphics filters