For basic cave level I want to try something new with rooms and corridors. I don't know if this routine has a specific name, but I have seen it before. It's filling the level by searching for next free place for a feature which can be something like room or corridor, or whatever. I guess features can also make branches so in fact this is somewhat like a maze algorithm, just with larger building blocks.
I don't actually need anything new for this algorithm, only the sequence of creation is something that has to be arranged using building bots like the maze routine does.
I think this is going to be the last big algorithm for level themes, then there are some static themes that need some work. Even I have tried to keep things simple it's taking quite a long time to finish 1.3, but I guess this is roguelike development.