PCem is a software-only PC emulator that currently (in repository) emulates targets from XT 4.77MHz to Mobile Pentium MMX 300. It requires a Intel Core i3/5/7 to run well.
Recent patches with Slirp networking led me to try this out.
The image is shifted because the SDL implementation has an issue with the 3dfx GL ICD (which can be fixed,
this also occurs with real hardware). 3dfx Voodoo Graphics is the only working 3d chipset it can emulate ATM, and apart from this offset, oa "looks" fine in it. Should mention it runs 1-7 FPS atm since OA is such a bloat.
(also i've made a very minor contribution to this emulator by porting my voodoo dac filter to C)