You may find this article helpful: Project Server vs Project Online vs On-Premise vs Project Lite vs PPM vs EPM [1]
You may find this article helpful: Project Server vs Project Online vs On-Premise vs Project Lite vs PPM vs EPM [1]
Links:
[1] http://www.pmconnection.com/modules.php?name=News&file=article&sid=112
[2] http://www.planningplanet.com/forums/microsoft-project