Limitations of SQL Server Express

My hosting provider (Rackspace) is offering a fully managed dedicated server with SQL Server Web version () installed. My company handles web development, and has about 20+ clients using ASP.Net + SQL Server 2005.

I am thinking of cutting down costs by installing the free SQL Server 2008 Express instead. I am aware of the 1GB RAM and 4GB/database (is that correct?) limitations. What I would like to know is:

1. Is there any limit to the NUMBER of databases I can install with the express edition?
2. Are there any other limitations I should be wary of? I am a bit concerned about having to set up the database backup - with the express edition it might a lot more difficult.
3. Any other advise?

There are a number of limitations, notably:

• Constrained to a single CPU (in 2012, this limitation has been changed to "The lesser of one socket or four cores", so multi-threading is possible)
• 1GB RAM (Same in 2008/2012)
• 4GB database size (raised to 10GB in SQL 2008 R2 and still same in as of SQL 2019) per database

http://www.dotnetspider.com/tutorials/SqlServer-Tutorial-158.aspx

https://learn.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2019?view=sql-server-ver16#Cross-BoxScaleLimits

With regards to the number of databases, this MSDN article says there's no limit:

The 4 GB database size limit applies only to data files and not to log files. However, there are no limits to the number of databases that can be attached to the server.

However, as mentioned in the comments and above, the database size limit was raised to 10GB in 2008 R2 (and is still 10GB as of SQL 2019). Also, this 10GB limit only applies to relational data, and Filestream data does not count towards this limit (http://msdn.microsoft.com/en-us/library/bb895334.aspx).