What are the best (or any) open source libraries for regular or context-free grammar inference from a set of examples believed to be generated by a common grammar? I'd prefer a good library in Java, Python or Ruby, but of course beggars can't be choosers.
I did some googling, but couldn't find any actual implementations, though I did find plenty of interesting references. This library looks interesting, but I couldn't find it available for download anywhere.
Edit (2011-11-14): For clarity (though I'm not sure how you all misunderstood), the question was about grammar inference, not grammar generation or parsing. In other words, given a set of strings which accord to an unknown grammar, find the most restrictive grammar which they all satisfy.
I have not used them yet, but I had this identical question and (after much searching) found these two libraries, at very least:
Unlike the other answers to the question, these are actual grammar inference libraries rather than parser generators.