The Atari++ Emulator is a Unix based emulator of the Atari eight
bit computers, namely the Atari 400 and 800, the Atari 600XL,
800XL and 130XE, and the Atari 5200 game console. The emulator is
auto-configurable and will compile on a variety of systems (Linux,
Solaris, Irix), and supports many emulation features.

Atari++ includes OS++, an open source replacement Atari 8-bit operating
system, so it's able to run many games and applications without the
Atari ROM images. However, for maximum compatibility, you probably will
want the original ROMs. To get them, install the atari800_roms package,
then use the atari++ GUI to set the ROM file paths to the images in
/usr/share/atari800/roms/.

Note: Atari++, by default, is built with a fancy set of CFLAGS
that the author includes in his makefile. If you're picky about
such things, or if you run into crashes or compile errors, try
setting FORCE_SLACK_CFLAGS=yes in the environment before running
atari++.SlackBuild