I was a very active programmer on the 0 A.D. team for a few years, but before the birth of this modern engine. The team is extremely high-quality, and the team leader/founder is very passionate about the project.
0 A.D. has been in development for over seven years (it is a very ambitious project). It does seem that over the past few years progress has slowed a bit. However, this is a very professional, modern engine which I highly recommend you take a look at! Programmers have even developed some of the more boring components such as level editors, converters for 3D Studio Max, etc., which are more rare to find in custom engines.
0 A.D. has been in development for over seven years (it is a very ambitious project). It does seem that over the past few years progress has slowed a bit. However, this is a very professional, modern engine which I highly recommend you take a look at! Programmers have even developed some of the more boring components such as level editors, converters for 3D Studio Max, etc., which are more rare to find in custom engines.
Here is the 0 A.D. home page, since it was not linked to earlier: http://wildfiregames.com/0ad/