@CBA OA
This is a 3rd Party Mod, only for Operation Arrowhead; Standalone users.
Not required when you use Combined Ops (Seperate or merged install).
Please see "Related" for cards tagged with CBA OA
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