Sql Server Editions and Comparison

Sql Server 2005 Editions Comparison

http://www.microsoft.com/Sqlserver/2005/en/us/compare-features.aspx

Sql Server 2008 Editions Comparison

http://www.microsoft.com/sqlserver/2008/en/us/editions.aspx

Compare Editions–Compact and Express for 2008

http://www.microsoft.com/sqlserver/2008/en/us/compare-specialized.aspx

Entity Framework can be used with Sql Server CE !

http://blogs.msdn.com/sqlservercompact/archive/2008/03/07/my-first-entity-application-against-sqlce.aspx

SQL Express v LocalDB v SQL Compact Edition
https://blogs.msdn.microsoft.com/jerrynixon/2012/02/26/sql-express-v-localdb-v-sql-compact-edition/