> Lua is a lot like Ruby or Python but about an order of magnitude faster
I'm surprised to hear either of those statements, both that Lua is a lot like Python and that it's an order of magnitude faster. Now, the last time I seriously looked at Lua was for my master's thesis work about four years ago, so I'm willing to believe that my impression of Lua is out of date. However, my experience on using it for a medium-sized project was that it is nothing like Python. My procedure for programming is
1) think of semantic construct,
2) think of how to express this construct in this language
3) type it in
My experience with Python is that step (2) is almost automatic - for whatever reason, every construct I'm used to using has a clear, terse expression in Python. And I've never spent an extended period writing Python, so I don't think it's because Python has really shaped the way I think. (The closest analogue to Python programming is using the STL in C++, in my experience.)
With Lua I had exactly the opposite experience. Every time it came to step (2), it felt like what I wanted to say was almost expressible in idiomatic Lua, but not quite. It just felt like I was running a race with a 50 pound backpack the whole time. Every time I tried to write a Lua script, I'd eventually throw up my hands and write my program in Python instead.
Now, it's certainly possible that I just never really understood Lua's paradigm that well, and that if I'd kept going I would eventually have reached enlightenment. I don't think so, though - tables just aren't that hard, oonceptually. However, the point is that, out of the box, Python gives me by far the least cognitive friction and Lua by far the most of any programming language I've ever used. I therefore have to strongly disagree that Python and Lua have much in common other than a small overlap in the niche they each fill.
And as for the order of magnitude speed difference, I find that hard to believe. Again, my information may be out of date, but when I looked at it Lua converted all numbers to double precision floating point numbers internally, which dragged its integer benchmarks down quite a bit. (In fairness, I think that was the same time frame where Python could only use primitive integers for the numbers 0-99, and had to box everything else.)