Licensing

hamsterdb Embedded Storage is available under several licenses - Open Source licenses (GPL 2 and GPL 3, with several exceptions for other FOSS licenses) and a "commercial", closed source license.

Dual Licensing

The hamsterdb Embedded Storage Commercial License allows customers to develop, use and distribute their application under standard commercial terms.

The hamsterdb Embedded Storage Open Source Licenses are available under the terms of the GNU Public License 2 or any later version (or other FOSS licenses). If you use the GPL license of hamsterdb Embedded Storage, you are forced to release your own product under GPL (or another open source license - see FOSS Exceptions), and anyone using your software must have access to complete source code, and must be able to modify and redistribute that software to anyone free of charge.

"Quid Pro Quo"

The rule of thumb for hamsterdb Embedded Storage licensing is: if you wish to derive a commercial advantage by not releasing your application under the GPL open source license, you must purchase an appropriate number of commercial hamsterdb Embedded Storage licenses. By purchasing commercial licenses, you do not longer have to release your application's source code.

Open Source Licenses

The GPL licenses have a long history in the software development world. There is a fair amount of explanations and comments in the web. The GNU project has assembled a list of frequently asked questions and their answers at http://www.gnu.org/licenses/gpl-faq.html.
Read the GPL 2 »
Read the GPL 3 »
Read more about FOSS exceptions »

The Commercial License

Commercial licenses are sold "per developer". If a company has three developers working with hamsterdb Embedded Storage, and does not want to follow the rules of the Open Source licenses, it has to buy three Commercial Licenses.

The term "Commercial" is a bit misleading - the GPL Licenses can also be used for commercial software development; however, it is not typical, and therefore we use the term "Commercial" to distinguish between Open Source and Close Source licenses.

Read the hamsterdb Embedded Storage Commercial License Agreement »

For legal reasons, you can find a German translation of the Commercial License Agreement here: hamsterdb Embedded Storage Kommerzielle Lizenz-Vereinbarungen »