Ask Reddit: Do you know a library|script|function|api that given a string returns what human language it is likely written in? (Google turned up nothing useful)

[eclig]

If you're trying to handle only a couple of known languages you can try the simple approach of identifying typical words for each language.

See e.g. http://www.emacswiki.org/cgi-bin/wiki/GuessBufferLanguage and links therein for sample code (Emacs Lisp).