Atari 2600

Yar's Revenge

Emulation

Javatari Source (github)
Javatari Java Emulator (javatari)
Jstella Source (sourceforge)
Jstella (ataritimes)
z26 (whimsey)

Homebrew

Atari 2600 homebrew
A-VCS-tek Challenge (quernhost)
Halo (atariage)
Medieval Mayhem (spiceware)

Development

batari BASIC (bataribasic)