1. CHECK constraints
2. IF EXISTS and IF NOT EXISTS clauses on CREATE/DROP TABLE/INDEX.
3. DESC indices
4. More efficient encoding of boolean values resulting in smaller database files
5. More aggressive SQLITE_OMIT_FLOATING_POINT
6. Separate INTEGER and REAL affinity
7. Added a virtual function layer for the OS interface
8. "exists" method added to the TCL interface
9. Improved response to out-of-memory errors
10. Database cache can be optionally shared between connections in the same thread
11. Optional READ UNCOMMITTED isolation (instead of the default isolation level of SERIALIZABLE) and table level locking when database connections share a common cache.

A complete list of SQLite releases in a single page and a chronology are both also available. A detailed history of every check-in is available at SQLite version control site.