MongoDB now released under the Server Side Public License

Eliot Horowitz


MongoDB has created a new software license called the Server Side Public License, or SSPL. The SSPL clarifies the conditions for making MongoDB publicly available as a service, to ensure we can continue to invest in building MongoDB for our users rather than in costly litigation over enforcing the AGPL. All subsequent versions and patch releases to prior versions of MongoDB made after October 16th, 2018 will be issued under the new SSPL.

Software as a service is one of the most significant and far-reaching paradigm shifts the technology industry has ever seen, and the market is moving to adopt it rapidly. This change is motivated by one simple truth: it is inefficient to operate software at scale when you just want to make use of its capabilities.

This should be a time of incredible opportunity for open source. The revenue generated by a service can be a great source of funding for open source projects, far greater than what has historically been available. The reality, however, is that once an open source project becomes interesting, it is too easy for large cloud vendors to capture most of the value while contributing little or nothing back to the community. As a result, smaller companies are understandably unwilling to wager their existence against the strategic interests of the large cloud vendors, and most new software is being written as closed source.

The best current solution for an open source company is to license their software under the AGPL, which requires a management stack used to operate that software as a service to be made available under the terms of the AGPL. This approach was believed to be good enough, as most people understood their obligations to comply with AGPL. However, as AGPL-licensed software like MongoDB has become more popular, organizations like the international cloud providers have begun to test the boundaries of this license. We would prefer to avoid litigation to defend the AGPL but instead devote our time to build great products for the community and our customers.

Since we own 100% of the copyright of MongoDB, one option available to us was to convert our open source license to a closed source license. We chose not to because we fundamentally believe in open source software. We believe an open source approach leads to more valuable, robust, and secure software, and it directly enables a stronger community and better products. We also could have licensed most of the code for the MongoDB server as AGPL while applying a closed license to some critical files. We chose not to do that because we believe that a uniform licensing approach, where all the code in a repository shares a single license, makes it easier to understand the obligations of using that code, leading to a stronger development community.

The community needs an updated open source license that builds on the spirit of the AGPL, but makes explicit the conditions for providing the licensed software as a service.

The SSPL is designed to make sure that companies who do run a publicly available MongoDB (or any software subject to the SSPL) as a service are giving back to the community.

It should be noted that the new license maintains all of the same freedoms the community has always had with MongoDB under the AGPL - they are free to use, review, modify, and redistribute the source code. We based the SSPL on GPL v3, with one new section that sets out an explicit condition for offering the licensed software as a service. We believe that the SSPL meets the standards for an open source license and are working to have it approved by the OSI.

Obviously, this new license helps our business, and that is one of the primary reasons we made this decision, but it is also critical for the MongoDB community. Over the past decade MongoDB has invested approximately $300M in research and development to offer an open source database to everyone, and this change protects our ability to invest aggressively in R&D to drive further innovation and value for the community.

I am convinced that the SSPL will have a positive effect on the open source community by encouraging increased investment into open source server-side software. As always, we are listening closely for your feedback, and we are eager to work with the community to drive towards a more open future.