Essential Business Serverhttp://msmvps.com/blogs/bradley/archive/2007/11/07/essential-business-server.aspxhttp://blogs.msdn.com/mssmallbiz/archive/2007/11/07/5955270.aspx Eric Ligman has the info on the name of the Mid Market Server formerly known as Centro.. now Essential Business ServerenCommunityServer 2008.5 SP2 (Build: 40407.4157)