Ingame Help journal entry gives you access to useful ACE information.
- Open the map
- Click "ACE" in the left side Journal list
- Select any of the sub items in the right list
Ongoing development 
ACE 1.13 RC5 [2011-12-09. Hotfix: 2012-04-27]
Stable
ACE 1.13 for OA [2011-12-23]
ACE 1.3 for A2 [2010-07-05] (Deprecated)
Dev blogs
Wheeled by Wagn v. 1.8.1