The newer developer-versions are stronger in comparison to the DD-Version.
Whenever they upload one that has important changes, they put it there with the results of the regression-tests.
Here's the site where you can get the development-versions alongside the programmers comments on what they have changed.
Just noticed there's a new one today with another good improvement.
http://www.computerchess.org.uk/ccrl/4040/
disagrees with you. which rating list puts stockfish at the top? how many games were played to decide that?
1. This is about Stockfish Don Dailey stable version, not recent devel ones (which are stronger).
2. 40/40 is not a serious time control, even for engines. You can ask mr. Thoresen if you doubt (although his site seems being temporarily down).
How are you sure the newer developer versions are stronger?
Also I'm not sure about Tcec and mr.thoresen since the site is down, he seems to be an authority figure. My only concerns are that there enough games to be conclusive, while the site I linked you has played many many games out from all sorts of engines and houdini is on top consistently across all tested time controls.