MSDE is the same database engine as Micrsoft SQL Server. It's very powerful, very stable, and very fast.
There are some limitations with it, though.
1. Any single database is limited to 2 gigabytes.
2. Performance degrades after there are more than 5 concurrent connections.
Microsoft does this intentionally. You see, they want developers to use MSDE to build their apps. Then, when more and more users start using the database, and performance slows down... The simplest way to improve performance would be to purchase SQL Server. SQL Server is not cheap, but it is fast.
My company uses it for our product. If the customer already has SQL Server, they can use that instead. If they decide to upgrade to SQL Server after using MSDE for a while, all they need to do is detach the database, copy it to the SQL Server machine, and reattach the database. Then, as a last step, configure the client app software to connect to the new SQL Server machine instead. The best part is... you don't need to change ANY code. None. Nothing. Not a single line.
I'm not sure if I would use MSDE in an ASP environment though. It's easy to imagine that the concurrent connections would be greater than 5 and performance would start to degrade. BTW, Access has similar performance problems. With Access, the theoretical limit is 255 users, but in practice, I found it to be more like 5 or 6.
As far as freeware gui tools... There are none that I am aware of. But since I have SQL Server and therefore Enterprise manager and Query Analyzer, I never had reason to go looking.
Hope this helps.
-George
Strong and bitter words indicate a weak cause. - Fortune cookie wisdom