Just a suggestion, but it would be nice to have some additional information in the documentation for connecting to an instance of Microsoft SQL Server, such as SQLEXPRESS. On our server here at work, I set it up with the instance parameter:
jdbc:jtds:sqlserver://localhost/openfire;appName=jive;instance=SQLEXPRESS
Related to that, is it possible to run from a LocalDB instance of the same server, and would it be recommended for/against? I have no plans to change, just curious. So far SQLEXPRESS is working for us.