Sleepycat License (sometimes referred to as Berkeley Database License or the Sleepycat Public License) is an OSI-approved open source license used by Oracle Corporation for the Berkeley DB, Berkeley DB Java Edition and Berkeley DB XML embedded database products. The name of this license is derived from the name of the company which commercially sold the Berkeley DB products, Sleepycat Software, which was acquired by Oracle in 2006. Oracle continues to use the name "Sleepycat License" despite not using the term "Sleepycat" in any other documentation.
According to the Free Software Foundation,[1] it qualifies as a free software license, and is compatible with the GPL.
The license is a strong form of copyleft because it mandates that redistributions in any form not only include the source code of Berkeley DB, but also "any accompanying software that uses the DB software". It is possible to circumvent this strict licensing policy through the purchase of a commercial software license from Oracle Corporation consisting of terms and conditions which are negotiated at the time of sale. This is an example of dual licensing.