LGrind is a pretty printer for a large number of programming languages using LaTeX. It is in the form of a separate preprocessor.

The licence is non-free, as it contains a no-sale clause. You might consider using the listings package instead, which is free; it also claims to be able to read the language definitions of LGrind. LGrind's output tends to be prettier, though, especially if you prefer non-monospaced fonts.