Orion uses bitboards (64 bit, signed integers) (U64). It is written in C++, and has its own user interface. I hope to someday add uci support for it as well. This engine is still in the early stages of development which prohibits me from commenting on its playing style. Currently, I would say that it plays very theoretically, but this could change.
Orion uses iterative deepening, hash maps, and quiescence searching. I would like to add null-moves as well when my engine is more developed. Currently, I am working on the rating system. I am constantly trying new ideas and weighing the time that those methods take with the improvement that they provide. It is a constant struggle of balance.