To begin in D coming from Python

[bearophile]

JAnderson:
> ok cheers.  I was just wondering if I should upgrade Lua since its one 
> of my bottlenecks however I'm using 5.

Lua is a fast dynamic languages, so if you find bottlenecks in your Lua code you may be doing something wrong (like using Lua for the wrong purpose, etc).
Anyway, can't you use the JIT? (http://luajit.org/ ), with that Lua becomes very fast :-)

Bye,
bearophile