SQLite is an open source software library that implements a self-contained (single file), zero-configuration, transactional SQL database engine. SQLite supports multi-user access, but only a single user can update the database at a time. It is largely an "untyped" system and all data is stored as strings. SQLite is widely used in desktop applications and consumer devices including cellphones, PDAs, and MP3 players.
Compared to Oracle
SQLite is similar to Oracle's Berkeley DB database in that all data is stored in a single file. However, unlike Berkley DB, SQLite also supports the SQL language and (for each row) triggers.
Migration to and from Oracle
An open-source library of Oracle-compatible SQLite functions has been written by Kansas State University students. Functions for other DBMS products have also been written.
The StepSqlite product from Metatranz LLC is a PL/SQL compiler for SQLite. It supports a subset of PL/SQL and can be used for code migration or parallel development between Oracle and SQLite.