ZSNES is an SNES emulator for i386 machines running Linux, DOS, or Windows. It allows you to play most SNES games on your PC. It also adds several enhancements not present in the original SNES such as filters to improve image quality, savestates to be able to save/restore your game at any time, and more.
Atari800 is an Atari 8-bit computer (400, 800, and XL and XE series) and Atari 5200 game system emulator for DOS, Windows, Amiga, Atari ST, Mac, and Linux/UNIX. It includes support for Atari cartridge ROMs, popular Atari disk images files, running Atari binaries directly from the host system, and accessing the host filesystem from within the emulated Atari.