In November of 1999, Sleepycat Software released Version 3.0 of Berkeley DB. 
The 3.X code line includes major new features, some of which require a
database format upgrade. Release 3 also modified the Berkeley DB API. 
Applications developed using version 2 of Berkeley DB will need to be upgraded 
in order to use release 3.X. 

For more information, refer to http://www.sleepycat.com
