Mark Manasse says:
I think that the OpenWindows release should be enough (no need to get the MIT X release), although there are a few things in Trestle that trigger devastating bugs in OpenWindows. But the only library we depend on is Xlib, R4 or later.
The main thing I know that crashes OW 2.0 is the code where we call GrabKey specifying AnyKey. You can either loop over all of the keys, or you can just comment out the call; programs won't run exactly the same, but you probably won't notice the difference.