Lua has its own corresponding social quirk: Its designers and community are <i>extremely</i> careful about adding anything to the language that wouldn't be trivially portable or would force any choices when running embedded inside another language/project. Consequently, there are several slightly different threading libraries, several slightly different bignum libraries, etc.<p>On the balance, I'm quite happy with the trade-off (it's strong pressure to keep Lua small, clean, and portable), but it makes using Lua standalone a bit weird. Particularly if you expect it to have "batteries included" like Python. It's very powerful combined with C, though, whichever is the primary language.<p>Also, the LuaRocks (<a href="http://luarocks.org/" rel="nofollow">http://luarocks.org/</a>) project is growing a central, CPAN-ish module repository, which helps.