Hello there, I've been helping develop for a server for a bit and we've recently fallen in love with Terrain Control. Unfortunately, we had a bit of trouble making our own bo3 structures with the tools that we'd managed to scrounge up. So I decided to make my own tools with python.
The most fruitful endeavor (schematic2bo3.py) is a program that converts a .schematic file into a .bo3 file, as well as the accompanying tile entities into .nbt files.
It seems to work pretty well for what we need, but I do have to warn you, it is a bit unpolished at the moment. If there seems to be significant interest, I might try to clean it up into a simple gui toolbox thing. Feedback is very much welcomed.