The only thing that is frustrating for me about DF (well ex-game frustration, not in-game) is that getting visualizations and interface changes in is gated by Toady. I dearly wish that this part could be taken over by the open source community; it would let him keep writing the simulator, and we would get some amazing VR-friendly worlds on top of the simulator.

I know that he doesn't want to support an open developer community because he, you know, wants to write his simulator and make it even more incredibly awesome than it is, but if only there were a way to get that code unlinked and into an API, it would make millions of people very happy.