[jmalicki]

Fair! I guess I didn't mean language as such, but as used.

But a lot of the monkey-patching kind of things and dynamism of python also means a lot of those sorts of things have to be re-checked often for correctness, so it does take a ton of optimizations off the table. (Of course, those are rare corner cases, so compilers like pypy have been able to optimize for the "happy case" and have a slow fall-back path - but pypy had a ton of incompatibility issues and now seems to be dying).

[dtech]

Javascript has a lot of the same theoretical dynamism, yet V8 and WebkitCore were able to make it fast

[eru]

Yes, with heroic effort. It's really a triumph of compiler / vm engineers over language designers.