stackless python

[Courageous]

>[1] - qualification: There are a few things that Python doesn't have
>      that do make it harder to optimize than it would be if they were
>      present, such as type declarations.  My point is that other
>      languages that are also missing these features have not found
>      them to be insurmountable obstacles.

And in any case, actually only a small part of the performance problem --
or at least for the performance problem within the order of magnitude
currently faced by Python.

C//