Stella is a program that will emulate the Atari 2600 VCS console. By using this emulator you will be able to load ROMs made for that system, especially games. Those ROMs are widely available on the Internet. Stella has been developed to work under many operating systems, like Linux, AcornOS, AmigaOS, DOS, FreeBSD, IRIX, OS/2, MacOS, Unix, and Windows.
The program’s interface can be controlled by either the mouse or the keyboard. You can configure it to show you video effects, which will mimic the image that you would obtain from a TV set (this console needed to be connected to a TV set to work, not to a PC monitor). Stella will also allow you to configure the audio settings, key controls, and joysticks. You can view the properties of the game "cartridge" that is currently loaded, and change the controls for each player. These settings can be saved to the ROMs for future usage. If you want to leave a program, all that you have to do is to press the ESC key. The ROM will be unloaded from memory and you will see Stella’s interface again.
I wrote this review with Stella installed under Windows 7, and it worked flawlessly.