SQLite: Protégé of PostgreSQL

The Keynote for PGCon 2014 by D. Richard Hipp

SQLite has become the most widely deployed SQL database engine in the world, with over two billion installations providing SQL database services for cellphones, web-browsers, cameras, and countless other gadgets and applications. But SQLite is not in competition with PostgreSQL. Rather, PostgreSQL and SQLite complement each other, with each engine targeting a different class of problems.

SQLite can be thought of as a derivative of PostgreSQL. SQLite was originally written from PostgreSQL 6.5 documentation, and the SQLite developers still use PostgreSQL as a reference platform to verify that SQLite is working correctly.