From the home page: With this driver you can access the files created by sqlite3 through the standard Qt sql module. The driver name is QSQLITE3. Although there are many other solutions to access such DB files, I think that using this driver has some advantages: --> You use the standard Qt interface so you can reuse exinting code or switch to or from other DB types quite easily. --> Soft transition to Qt 4: Qt 4 supports sqlite3, you can prepare your application now. qt-sqlite3 will be used by the next versions of kmymoney2.
Qt4 already supports sqlite3, and we won't add anything but bugfixes for Qt3.