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Versant & GPL :: Frequently Asked Questions


Where can I find more information about GPL licensing?

If you are using db4o under the GPL, please be certain to follow the guidelines specified in the GNU General Public License (GPL) text itself. In addition, there is a good collection of FAQs from the Free Software Foundation, the editors of the GPL, addressing a wide range of issues around the GPL.

Should I use the GPL or the commercial license?

Guidance on the best licensing option is provided in this free whitepaper about Versant's dual licensing model.

When using Versant under the GPL, when am I required to make my application "open source"?

If you are distributing your application only to users within your own company or organization, then you do not need to open source your software program.

If you distribute your application to users outside of your own company or organization, then you must make your application freely available, and you must open source your application code.
Important: Users outside your company may include (and are not limited to) partners, consultants, contractors, resellers, distributors, customers, affiliates, subsidiaries, and agents.

If you are an outside consultant developing a db4o-based solution for your client, then you must open source your solution, when you ship to your client.

When making my db4o-based application "open source" under the GPL, what are my obligations to publish the source code?

When you open source your application using db4o under the GPL, it is important that you make db4o and your derivative work - in source code - available to ALL db4o users, including the db4o Community who provided this product free of charge. It is not sufficient to publish your sources only to the users of your modified product. Your source code must be available to all users in the db4o community.

As such, Versant may ask you from time to time on behalf of the community to show evidence of free, public access to your source code in all its versions. As a GPL licensee, you hold the responsibility to reply readily to this request, or any other request from a db4o Community member or the Free Software Foundation, which acts as the GPL enforcing agency.

If you find it difficult to publish the sources with every shipment, on your website, or on a hosting platform like Sourceforge, you may find it useful to register your GPL project with the db4o community.

What are the benefits of registering my own derivative work with the db4o community, if I use db4o under the GPL?

If you find it difficult to publish the sources with every shipment, on your website, or on a hosting platform like Sourceforge, you may use the Projects section in the db4o Developer Community to register or even host the sources your project.

A project registration with the db4o community is considered 100% compliant with the obligation to make your sources openly available and protects you from any accusation of respective license infringements on behalf of Versant, who holds the copyright to the entire db4o core distribution and who is your GPL licensor.

In addition, you will get a lot of eyeballs from expert db4o users, who can look over your source code, suggest improvements or even participate in your project. At no additional cost, you can make the world's largest community for object database technology work towards your own project!

How do I register my own derivative work with the db4o community?

To register your GPL project as GPL compliant with db4o's community, just send a message to the community manager. Please provide:

  • A short, unique name of the project (choose carefully, cannot be changed)
  • A short description of your project or your modification
  • Your db4o community user name
  • Source code
    • a URL to the hosting site, if you host yourself, or
    • indicate if you want the db4o Community to host your source code in db4o's Download Center (example). In this case you will receive 'owner' rights to the respective folder to upload the sources and updates yourself
  • Indicate if you want to have your own, free WIKI topic set in our Projects section (example). In this case you will receive 'owner' rights to the WIKI topic set and can build your own project WIKI.

How can I use and distribute db4o under a free and open source license other than under the GPL (e.g., Apache, BSD, LGPL, EPL)?

For the purpose of use and redistribution with other free/open source software licenses, db4o has established the db4o Opensource Compatibility License (dOCL).