License Question: Can I sell apps I write in free express editions?

For my senior seminar project at my college I am writing a database application for a local business.

1.) Can I legally use VB Express and SQL Server Express to write this application (Just a little hesitant since they're free)

2.) Would I be able to sell this application or are express editions solely for "practice"

Any insight or links would be most appreciated.

Thanks,

Ryan