Greg is correct in that you can create your own DAL just like the SQL Server, Oracle, VFP, etc. by inheriting the DbDataSourceItem and then implementing the appropriate statements. Since we provide source code with SF, you can even copy over one of the other DALs and then implement the changes for your desired DB.We are going to provide additional providers in the future. However, we do not have plans to create one for VistaDB. We are familiar with this database and have done a fair amount of research on this DB. There is very little demand and with the advent of SQL Server 2005 and SQLEverywhere which integrate much more smoothly into .NET since it was designed by Microsoft...and it is free and faster than VistaDB. I know that VistaDB states that they are not a competitor of SQL Server Express, but ultimately that is the database that people generally end up going with over VistaDB.