Believe me, I would do backflips if someone wanted the BK source base, it's got almost 2 decades of my work in it, north of 140 man years. It's a lot to just let fade away.
But I assembled a team of people better and smarter than me, I did my best to keep the code simple but I didn't always succeed.
If you, or anyone, wants to pick it up, I'm happy to answer questions.