On Thu, 24 Nov 2011 12:18:50 +0000, Regan Heath wrote: > The source for Minecraft (written primarily in > Java) was going to be released
Hasn't been yet, but it wasn't going to be released as OSS and only intended for modding. So I don't know what the licensing rules would entail, but there is a clone in C++ being created: https://github.com/celeron55/minetest it likely won't get traction. The community exists, maybe a small subset can be captured, but a community following really won't happen until Notch is behind it (which might actually be doable). Doom 3 is a massive undertaking and not really feasible. What I would suggest making D usable for modding. And like many here, this task isn't for me.
