Yes. PL/pgSQL is the default AFAIK (been away from active use of Postgres for a few years). PL/pgSQL is basically the same as Oracle's PL/SQL, which has a very Pascal-like syntax.

I played around with PL/Lua 5 or 6 years ago, and liked it, but the project/idea got sidelined for other reasons so I never got very deep into it.