I'm one of the co-founders in this project. Thanks for taking a look at Rainbird.
Currently to integrate you'll either need to use our REST api or a Javascript agent - essentially a little themeable widget you can embed in your site. This means that we host your knowledge base and you need do to be on-line to access what you've built.
We do have plans to provide a version of our engine that could be used off line or self hosted. Although we don't expect this to be available in the near future.