With the latest Mesa Git code as of this morning, I ran GitStats to see how the development activity and contributors have changed over 2013 and in comparison to years prior.
In getting started, Mesa is currently at 1.348 million lines of code in 4,108 files and that work came over the course of 60,268 commits from 595 authors.
So far in 2013 there's been 5,576 commits to Mesa that have added 415,552 lines of code while removing 342,420 lines of code, or overall a net change of 73,132 lines of code were added to mainline Mesa so far in 2013. 5,576 commits so far in 2013 puts it behind Mesa in 2012 where there were 6,077 commits or in 2011 where there were 6,788 commits. The peak year was in 2010 with 12,269 when lots of code re-factoring, DRI2, and other low-level changes were happening to the Linux graphics stack.
Mesa in 2013 has certainly advanced a lot, as covered by the hundreds of Phoronix articles this year covering the open-source Mesa graphics drivers. Information can be found mostly within the Phoronix display driver articles and Mesa news items. A few days ago I also focused on a 2013 Intel Haswell Linux year-in-review while the Radeon Gallium3D driver and other Mesa 2013 recap articles will be out in the days ahead.