Psyco was great. Add two lines of code, suddenly everything is (at least a little, often a lot) faster.
It was great. It showed that it is actually possible to run fast Python from within the standard interpreter with excellent compatibility. The only downside I remember was the memory usage.
Why isn't everyone using it then?
Doesn’t support modern Python versions.
>12 March 2012
>Psyco is unmaintained and dead. Please look at PyPy for the state-of-the-art in JIT compilers for Python.