The StrataFrame and StrataFrame Internal databases are not used to at runtime. They are only used by the Database Deployment Toolkit and the Business Object Mapper. So, when you deploy a StrataFrame application, you only need to deploy the runtime DLLs with your application (which are referenced by your app, and will most likely be pulled in as dependent assemblies in your install). As for SQL Server or SQL Server Express, that's entirely up to you. Since you don't need to deploy our databases onsite, you've got free reign on which version you want to use.