It's being programmed in java, because we (the team) know java.
(I know, I know, "java is bad", but it's a nice language that we know, and as long as we optimize our code it'll be just fine.)
The general idea is to make a fast, moddable sandbox game with special features like support of lua modding (server -> client like Source games do) and a pre-supplied API. Some in-game planned features are cool texture-loaded 3D models and a neat inter-connected technology web (with some simple emulation of data going between compuers as it actually does, as bytes, with some stuff that can understand those bytes, and in-game programming of those computers that can edit the drivers/os/what have you)
Also infinite worlds (on all axes, x/y/z) as much as feasibly possible (java has limits to the size of its numbers, and it would be unnecessarily lag-inducing to add support for literally infinite worlds. Worlds stretching from 2147483647 to 2147483648 on each axis should be enough for anyone)