Hatari is an Atari ST/STE/TT/Falcon emulator for GNU/Linux, BSD, Mac OS X, Windows and other systems which are supported by the SDL library...

Hatari supports the emulation of most of the ST and STE hardware, including some special tricks like raster interrupts, border effects and PSG sample sound. A joystick can be emulated with the cursor keys or with a real PC joystick. Hatari also features the possibility to "mount" a directory of the host system as a ST drive, or to use images from an original Atari's hard disk. Hatari is also able to emulate the additional hardware of the TT or Falcon machines, like the Videl video chip or the DSP 56001. However, note that TT and Falcon support are currently still in development and experimental.