Paul Robson's A26  
   DOS based open source emulator.
   http://members.aol.com/autismuk/emu.html

StellaX  
   Windows 9x, NT and 2000 port of Stella.
   http://www.emuunlim.com/stellax/

z26  
   An open source emulator for DOS, Linux, and Windows based on Paul Robson's A26.
   http://www.whimsey.com/z26/

PCAE  
   An open source emulator for DOS and Windows, written in Pascal/Delphi.
   http://pcae.vg-network.com/

Atari 2600 Emulator for GBA  
   Emulation project for Game Boy Advance with details and screenshots.
   http://www.otakunozoku.com/gbavcs/

Stella  
   An open source emulator for DOS, Linux, MacOS, Unix, and Windows.
   http://stella.sourceforge.net/

Dan B's Atari 2600 Tech Page  
   An open source emulator (Virtual VCS) for DOS and technical information.
   http://atarihq.com/danb/a2600.shtml

Imdylanks Atari Roms  
   A collection of ROM Images packed in three files.
   http://www.geocities.com/imdylank/user.html

Atari VCS Preservation Retrogaming Archive  
   514 ROM Images in one zip file. [Requires Flash]
   http://atarigamer.tripod.com/

Acorn Virtual 2600  
   Emulator port for Acorn RISC OS.
   http://www.mnementh.co.uk/v2600/

Virtual 2600  
   Historical look at Alex Hornby's Virtual 2600 emulator. Virtual 2600 is an open source emulator for DOS and Unix.
   http://www.hornby.dsl.pipex.com/v2600/

AtariAge: 2600 Emulation  
   Resources and links to the most popular emulators and utilities.
   http://www.atariage.com/2600/emulation/

GP32 Atari 2600 Emulator  
   Port of Virtual VCS emulator to the GP32.
   http://www.atariage.com/2600/emulation/GP32/