I started a new mod project OpenHV. It is a sci-fi themed RTS using most of its artwork from the unreleased Hard Vacuum game. The assets fall under the liberal Creative Commons Attribution license. Sounds are .wav and sprites are loaded from .png files so it uses open standards where possible, which also eases the development.
The game is still very much work in progress. No release yet.
Yes, Rusted Warfare uses the same terrain tiles. They should mention somewhere that it's from Daniel Cook.
The main goal is to have a game with Open Source assets both sound and graphics. It should also not be a bland CnC clone, but distinguish itself. Some bigger features inspired by the unreleased original are: