Dubhthach wrote: Xming as well:
http://freedesktop.org/wiki/Xming
Unlike Cygwin/X you just install an X-server and don't need any of the cygwin stuff.
zappa wrote: EDIT: I'm not sure about OpenGL support in it, anyway. Another option might be XWin-32, running in demo mode (a session can last 2 hours, then it mus be restarted)
XMing does indeed support OpenGL and GLX, but it's a bit buggy.
X-win32 does OpenGL and GLX, and it's reasonably stable, but it's incredibly slow.