The SQLite website recommends using the “sl3” extension to signify that we're working with an SQLite version 3 database. If we examine the resulting file, ljdata.sl3 using the strings command, we see ...

New AUP3 Audacity project file format This new format is an SQLite 3 database that Audacity says should make editing audio a little faster. However, closing and saving a project will be a bit slower.

SQLite Subsonic Provider SQLite LINQ Provider The LINQ provider allows for .NET 3.5 developers to be able to take advantage of the new LINQ framework and use SQLite as the back-end data store.