"I think when he asked about an IMDB what he really wanted was an in-proc db... "
I thought IMDB stood for In Memory DataBase. Am I wrong? "I know I could tell them to use MSDE, but I am unsure of the target machines (Windows 9x etc) and don't want to be supporting my app and MSDE" I really think the way to go with this is to use MSDE. That way you only have to worry about one type of backend. As far as supporting MSDE, not much to do if it's just one user. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
