python, for starters. scipy/matplotlib dont work with osx's shipped python

  Lots of open source software doesn't even work on osx.

Failing to work out of the box (for whatever legal reasons) is very different from "doesn't even work". Finality was implied in your original post.

Enthought has binary distributions for the various platforms for a long time.

Sorry i meant "doesn't compile", which is the essence of open source programs anyway. If that wasn't an issue on OS X there wouldn't be so many porting projects (macports, fink etc). And if you work with non-popular (e.g. scientific) programs that's not even an option.

Compiling software is not trivial, that's why you have macports, fink, etc... Like you have apt, portage, pacmacn... on Linux distros or ports on FreeBSD.

With the _shipped_ python. But you can install a python on osx they work with?