There's a database engine that looks amazing for a free tool and that is Scimore. Have you had much experience with it? If so, how does it rate..particularly against Firebird? How resilient/self reliant is it? (Meaning how much downtime/maintenance is expected?) The scale out capabilities also look very interesting. I just downloaded it and have been playing around and so far it looks good. I had been looking for an easy to deploy single-user type embedded database (which Scimore has an option) and was toying with MS SQL Compact Edition and SQLite and remembered this database from a trial a few years ago. (Windows platform) I was about ready to settle in on SQLite but started thinking about other projects which are multi-user and wanted to stick with a single solution...which is why I started looking at Firebird as well.