MS SQL Comparison

MSDE 2000 SQL can run on dual-processor machine.
MSDE 2000 can have up to 16 instances.
MSDE 2000 has 2GB database size limit.
MSDE 2000 does Not come with GUI tools.
MSDE 2000 is crippled with workload governor. Once the governor has been activated, one factor determines how much the database engine will slow down: the cumulative number of logical reads and writes of data pages by all the active connections.

MS SQL Server 2005 Express Edition is a freeware ´lite´ edition of SQL Server 2005.
MS SQL 2005 Express only utilitizes one processor.
MS SQL 2005 Express can have up to 50 instances.
MS SQL 2005 Express can utilize up to 2GB of RAM.
MS SQL 2005 Express can utilize only up to 1GB of RAM.
MS SQL 2005 Express has a 4GB database size limit.
MS SQL 2005 Express comes with GUI tools.
MS SQL 2005 Express .NET Framework 2.0 is required.
MS SQL 2005 Express does not have a workload governor.
MS SQL 2005 Express supports only Windows 2000 SP4, Windows XP SP1, and Windows Server 2003 (including Web Edition).