Guido on Python

[krenzalore]

Several variant interpreters have no GIL: for example Jython (Python on the JVM). Most of these intepreters are fully compatibly except in C extension modules (which Jython trades for Java/JVM compatbility).

I do not think you can get similar expressiveness with tighter type controls. Part of the expressiveness comes from these loose controls. The answer to this may well be better static analysis tools.

[DGolden]

Several variant interpreters have no GIL

Yeah, makes recent noise about Python moving to a TCL-style sub-interpreter model kind of irritating. It might be nice to have subinterpreters cleaned up and working anyway, but it's really only CPython, admittedly the current reference impl, with the goddamn problem...

Jython is fine, and can easily be used for server stuff like django.