yod is a library which will procedurally generate a constructed language based on various rules which can be supplied by the user, or a completely random language if no rules are specified. yod handles everything from phoneme inventory, to phonotactics to syllable structure, to creating a lexicon, to generating grammatically sound sentences.
The source code for yod can be found at http://github.com/Cesque/yod/
My thesis, "Creating a library to aid in constructed language generation", which explains the development and purpose of yod, can be found here.