Key Criticisms of the Server Side Public License (SSPL)


The Server Side Public License (SSPL) was introduced by MongoDB, Inc. in 2018 as a way to address concerns about cloud providers profiting from open-source projects without contributing back to them. The SSPL has generated controversy and faced several criticisms:

  1. Not Officially Open Source: The SSPL hasn’t been recognized by the Open Source Initiative (OSI) as an open-source license. This means that software under SSPL does not meet the OSI’s Open Source Definition. One of the fundamental principles of open-source licensing as defined by the OSI is the freedom to use the software for any purpose without restriction.
  2. Too Restrictive: One of the fundamental tenets of open source is the freedom to use, modify, and distribute software. The SSPL imposes restrictions on providing the software as a service, which some argue goes against the spirit of open source.
  3. Vague Language: Critics have pointed out that the language used in the SSPL is somewhat ambiguous. Specifically, the definition of what constitutes a “service” can be open to interpretation, potentially leading to legal gray areas.
  4. Business Concerns: Some businesses are wary of using or contributing to SSPL-licensed software because they fear it could affect their ability to offer services in the future or because they believe it might lead to licensing complications.
  5. Fragmentation of the Open Source Ecosystem: Introducing new licenses, especially controversial ones, can fragment the community. Having many different licenses with slightly different terms can be confusing and counterproductive.
  6. Reaction from Cloud Providers: Major cloud providers, like Amazon Web Services (AWS), responded to the SSPL by creating alternative versions of the software (e.g., Amazon’s DocumentDB as an alternative to MongoDB) to avoid the SSPL’s restrictions.
  7. Licensing Chain: There are concerns about how the SSPL’s terms might affect other software that interacts with SSPL-licensed software. The SSPL requires that any software that’s offered as a service in conjunction with the SSPL software must also be open-sourced, which can have implications for software integration and composition.


It’s worth noting that MongoDB, Inc. introduced the SSPL to address what they saw as a significant issue: major cloud providers monetizing open-source software without giving back to the community or the original developers. However, the SSPL’s approach to solving this problem has led to debate within the tech community about the best ways to balance open source principles with sustainable business models.