3B2 Desktop is the standard desktop version for your OS on an individual licence.
3B2 Batch server version for black box and automated production, single processor only, not scaleable.
3B2 ACS Server (Advent Composition Service) is a scaleable composition service that was developed to run with 3B2 Batch on Windows 2000/XP and provide the following functionality:
The system has two major components, ACS and a composition agent:
Being scaleable 3B2 ACS server has the ability to considerably reduce composition time. The setup can range from a single machine with one ACS controller and one copy of 3B2 (the composition agent), to one server hosting the controller and multiple machines each hosting one or more composition agents.
Follow the flash overview for a pictorial presentation of all 3B2 installations including ACS Server:
See also