In my experience (doing some fairly heavy computation in nested loops), PUC Lua is faster than Python but slower than recent versions of Ruby.
LuaJIT is at least 10x faster than all three.
LuaJIT is at least 10x faster than all three.
Ruby faster than PUC Lua? That doesn't sound right. You're talking about Ruby MRI?
Not the original MRI, but YARV. For this particular program, the performance of different language interpreters is:
MRI (Ruby 1.8) < CPython 3.5 < CPython 2.7, PUC Lua 5.1/5.3 < YARV (Ruby 1.9/2.3) < LuaJIT -joff
There is a factor of ~5x between the slowest and fastest of these interpreters. LuaJIT with the JIT enabled is ~10x faster than even its own interpreter.
Unfortunately, as a Pythonista (although one whose paid work is mostly in JS these days), I can't imagine that happening in the Python community (not to our credit). Too much ego wrapped up in CPython.
YARV? No.
YARV is the current official Ruby interpreter - it replaced MRI in this role from Ruby 1.9 onwards.
(http://www.atdot.net/yarv/rc2006_sasada_yarv_on_rails.pdf page 15)