Psyco lets you run your existing python software much faster, with no change in your source.

think of psyco as a kind of just-in-time (jit) compiler, a little bit like java's, that emit machine code on the fly instead of interpreting your python program step by step. the result is that your unmodified python programs run faster.

the plan for the next release is to include a fast low-level interpreter that can be used on non-intel processors. it will finally make psyco portable -- although of course not as fast as it could possibly be if it could emit real machine code.