An Open Core Licensing Model

There is a concept of an Open-Core License (OCL) model for building a business on open source that is growing in popularity among open source companies. This has been discussed for a while now and I’m a big fan of the concept. In fact, I MindTouch is employing this model and I recently spoke at OSBC on this topic. OCL strikes me as a very natural way to create balance between the needs of the company and those of the community of open source users. Other alternative models include dual-license model or even cripple-ware, a model in which the open source core is disabled or diminished in some way to get users to upgrade to a paid commercial version (think performance, number of CPU, users, etc…).

I think the best description of OCL is by Andrew Lampitt of JasperSoft, who I think coined the term (not sure). Rather than me explain his thinking I’ll quote:

So I propose the following for the OCL business model:

- core is GPL: if you embed the GPL in closed source, you pay a fee

- technical support of GPL product may be offered for a fee (up for debate as to whether it must be offered)

- annual commercial subscription includes: indemnity, technical support, and additional features and/or platform support. (Additional commercial features having viewable or closed source, becoming GPL after timebomb period are both up for debate).

I completely agree. In fact, Matt Wilkie, a MindTouch open source user brought up exactly this in a recent blog post comment. Here’s how I see it:

Open Core Licensing OCL Model

What it says above is, today’s low value adds become’s tomorrow’s commodity capabilities that get rolled into the free and open core meanwhile new value adds are added. Absolutely the right approach in mind except I would modify one thing in the above graphic (provided by Mike Diliberto – a MindToucher) and that is where it says in the cloud thingy it says “New features from user requests, community projects” should read: “New features from customer and user requests”.

Thanks for the question Matt and thanks for the mostly correct graphic Mike!


  1. So does Open Core licensing replace the GPL? Is it an existing license.

    While I agree with the business constructs, it seems that the attempt to place restrictions on any of the Open Source Initiative licenses goes against one or more of the precepts of OSi licenses. Not to mention the impact and infringement on the terms of GPL itself.

    • Bizarre, my response to your comment didn't post last week. :-( Drat this plugin.

      Hi Dave! Long time no see. I haven't seen you since the Open Source Think Tank in Paris. I hope you're well. :-)

      The concept of Open Core does not conflict with OSI licenses or GPL. By the way, MindTouch uses GPL. Instead it builds on GPL or other OSI approved licenses. Specifically, I'm referring to layering additional functionality on top of the open core that is maintained under a non-open source license. In the case of MindTouch we use a shared source license for the additional value add layers. Make sense?

  2. Hi Dave! I missed you at the Open Source Think Tank in Napa this year. Been a while. :-)

    No, this doesn't at all replace or infringe on GPL or OSI licenses. I think the confusion may stem from calling it "Open Core License" or "OCL". It's probably better to just refer to it as Open Core and open source licensing. Anyway, at MindTouch we release MOST of our work under GPL v2 to the public. We hold back some premium value adds (labeled confusingly in the above graphic "core value add") and low value adds as proprietary non-open source layers, but release this under shared source. Examples of these value adds include: a Desktop Suite for publishing from Microsoft Office, LDAP/Active Directory module, adapters CRM adapters (SugarCRM, Salesforce, etc…), database adapters, reporting tools, management tools…you get the idea. As we add more premium value adds, old premium value adds become low value adds and old value adds will get released into GPL. When we layer proprietary modules and adapters on top of MindTouch Core this is done cleanly without violation of the GPL. See: for insight into how we do this or just look at the source code here:

  3. Open Core doesn't replace the GPL, it specifically leverages it. The above article clearly outlines that.

    This approach offers a balance of OSi-friendliness while keeping the business folks ("commercial" leaning people) at bay.

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