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.

I can't speak to if SF will decide to support any of these other databases, but all of these can be supported now.



It is as simple (er...ok simple probably isn't the right word) as implementing a DbDataSourceItem abstract class for any of them. I haven't tried this myself (I'm using MS SQL Server), but I've also thought VistaDB would be interesting to use and have contemplated it.



So, I have no idea if SF will ever support any of these dbs (likely depends on demand), but if you need to use a non-SF supported db, you could do it today, theoretically, assuming the db has an ADO.NET provider.



Hope this helps!

It would be nice to see support added for some other databases such VistaDB, PostGRESql, SQLite, Firebird, MySQL, Advantage etc.



VistaDB is very interesting since it is written entirely in .NET.