bit late like usual : ) but newest version supported for online play. major changes to visuals since last posted release.

About the 3.1 series:
The 3.1 series is the first based on the new netcode, with new terrain renderer and many other changes. The main target are systems capable of OpenGL 2.0 (with shaders), but at least the important things like team colours should work with OpenGL 1.4+ (some things might look strange though).

Configuration uses a new directory, if you want to use old mods/maps/savegames, you need to copy them (see FileLocations). Note that savegames from 2.3 and 3.0 are incompatible, only those from newer master snapshots might still work. For mods it depends on what they do, don't expect old mods to work either.

2.3 is now officially unsupported.

Changes since the 2.3 series:
(Items marked with a * were already in the cancelled 3.0 series)

New terrain renderer*
Support for 3*/5*/6*/7*/9/10 player maps
Targetting by line of sight, preventing shooting through terrain or too early*
Gates in multiplayer games
New deterministic netcode that makes sure the same things actually happen for all players, should be much more cheating-resistant
New power system, power is deducted in full at the start, and when power is low, in the order things were queued
Unit targeting is more intelligent, they won't all shoot one target when one shot is sufficient
Remove fog of war/mist options in favour of a combined explored/seen mode
Stored templates. Automatically adds a unit design when all needed research is available
Command line parameters now need a '=' (which was optional before), e.g. --resolution=1400x1050
Apple systems: Drop support for PPC and Mac OS X 10.4, add support for 64 bit Intel on Mac OS X 10.6+