# Berkeley DB Reference Guide: Release 4.0: introduction
Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

###

Berkeley DB Reference Guide:
  Upgrading Berkeley DB Applications

### Release 4.0: introduction

The following pages describe how to upgrade applications coded against the Berkeley DB 3.3 release interfaces to the Berkeley DB 4.0 release interfaces. This information does not describe how to upgrade Berkeley DB 1.85 release applications.

Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.