tuxnes is a NES emulator.

Features:
- open source
- dynamic recompilation from 6502 opcodes -> x86 native opcodes
- mappers: 0, 1, 2, 3, 4, 7, 9, 11, 32, 66, 99
- experimental mappers: 15, 22, 23, and 71
- gzip and zip file support
- game saving
- built-in disassembler
- joystick support (2- & 4-button)
- experimental sound support
- capture screenshots in X pixmap (xpm) or portable pixmap (ppm) format
- Game Genie code support
- trainer support
- alternate palette support