Seeing the authors of Steem are dragging their heels over making their emulator open source, can I suggest a port of the Atari ST emulator
Hatari? It's source is
here. It is SDL mind.
However, unlike WinSTon it is able to emulate the STE architecture and run certain games that WinSTon doesnt like such as R-Type for example.
Not meaning to bump the above post par se, but for the same reasons about WinSTon I can suggest another alternative: when Chui wrote
for the Dreamcast he combined the sources of CaSTaway & Hatari and it has also been ported to Windows. The source is available
. SDL again, I do not know if that represents a problem.