Steem SSE

Steem SSE is an Atari ST emulator developed from Steem Engine, the popular emulator by Anthony and Russell Hayward whose source code was released in 2004. The SSE project was started by a developer using the name Steven Seagal to make Steem far more accurate.

It emulates the ST and STE, and it is known for its precise emulation of the Shifter, the MMU and other timing details that demos use for tricks such as opening the screen borders. It also emulates the Blitter, the floppy drive controller with support for STX and other protected disk images, MIDI and ACSI hard disks, and it keeps Steem’s well-liked interface, with a debugger in a separate build.

Steem SSE is actively developed, and version 4.2.1 was released in August 2026. There are 32-bit and 64-bit builds for Windows and Linux, and a libretro core. It is released under the GNU GPL.