SQLite includes a number of extensions providing additional functionality. All extensions are disabled by default and you need to take steps to have them available at compilation time, to enable them and then to use them.
FTS3 is the third version of the full text search extension. It makes it easy to find words in multi-word text fields. You must enable the extension via setup.py build flags before it will work. There are no additional APIs and the documented SQL works as is.
Note that FTS4 is some augmentations to FTS3 and are enabled whenever FTS3 is enabled as described in the documentation
The ICU extension provides an International Components for Unicode interface, in particular enabling you do sorting and regular expressions in a locale aware way. The documentation shows how to use it.
Provides resumable bulk update intended for use with large SQLite databases on low power devices at the edge of a network.
The RTree extension provides a spatial table - see the documentation. You must enable the extension via setup.py build flags before it will work. There are no additional APIs and the documented SQL works as is.