"Atari 2600 Console Emulator"
Atari 2600 was the first console to achieve great sales success and be really popular with a large part of the public. They are mythical their games in cartridge format that were the first that were sold of this style and that allowed to interchange the games. With the same machine you could play different games. This today seems silly, but at the time it was what made this console so popular and soon it was common for the games to be sold separately from the machine.
Stella is an emulator for Windows computers of this console so popular in the late 70's. Thanks to Stella you can play Donkey Kong or the original Super Mario Bros again.