SQLite is an open source database for embedding into applications. SQLite is a powerful and flexible database system. It is not multiuser. It is mostly used as an “embedded” database that is, as part of an application. Like an email application. It is very fast and is basically unlimited in size with a limit of 140 terabytes.

What we like about SQLite:

• Absolutely free, open source, with no licensing retrictions.
• Easy setup. No configuration at all.
• Perfect for embedding into applications.
• Updates are made frequently.

What we don't like about SQLite:

• Single user only with no user management. Some have made attempts to work around this and it does work in some cases but if you need multiuser then you should choose multiuser. If two users are working on the same record then their work may cancel one another.
• It does not scale well. As needs become more complex the lack of multiuser and some other features become a problem.

SQLite is a very highly regarded database system when used for the right application. Here is a list of some of the more well known users. Apple uses it for a number of products. http://www.sqlite.org/famous.html