threading support in python

[skip at pobox.com]

    Sandra> However, I don't expect that the GIL can be safely removed from
    Sandra> CPython.

It was removed at one point in the dim, dark past (circa Python 1.4) on an
experimental basis.  Aside from the huge amount of work, it resulted in
significantly lower performance for single-threaded apps (that is, the
common case).  Maybe more effort should have been put in at that time to
improve performance, but that didn't happen.  Much more water has gone under
the bridge at this point, so extracting the GIL from the core would be
correspondingly more difficult.

Skip