Server Side Public License

The Server Side Public License (SSPL) is a software license introduced by MongoDB Inc. in 2018. While the company maintains that it grants "all of the same freedoms the community has always had with MongoDB under AGPL", the SSPL is not recognized as an open-source license by the Open Source Initiative (OSI), which describes it as a "fauxpen" source license instead.
License terms.
According to MongoDB, the SSPL is based on the GPL3 license, with the addition of a new section that "clearly and explicitly sets forth the conditions to offering the licensed program as a third-party service," requiring that those making the software publicly available as part of a "service" must make the service's entire source code available under this license.
According to Packt writer Richard Gall, the most important new sentence in the license reads "If you make the functionality of the Program or a modified version available to third parties as a service, you must make the Service Source Code available via network download to everyone at no charge, under the terms of this License."
Licensed software.
In October 2018, the MongoDB database was released under the SSPL. The Debian, Red Hat Enterprise Linux, and Fedora Linux distributions subsequently dropped MongoDB, citing concerns about the SSPL. Amazon released a compatible but proprietary service named DocumentDB, and it appeared that the SSPL didn't succeed in capturing cloud revenue for MongoDB.
In November 2020, Graylog announced that version 4.0 of its source-available release will be licensed under the SSPL.
In January 2021, Elastic announced that future versions of their code in Elasticsearch and Kibana, licensed until then under the open-source Apache 2.0 License, would be dual-licensed instead under SSPL and their own Elastic license. Critics of the re-licensing decision predicted that it would harm Elastic's ecosystem, and Amazon responded with plans to fork the projects for continued development of versions licensed as Apache 2.0. Other users of the Elasticsearch ecosystem, including Logz.io, CrateDB and Aiven, also committed to the need for a fork, leading to discussion of how to coordinate the open source efforts.
Certification with OSI.
In 2018, MongoDB submitted the license to the Open Source Initiative (OSI) for approval. The company withdrew its submission in 2019. In January 2021, following the re-licensing move by Elastic, OSI released a statement declaring that the SSPL is not open source and that it is a "fauxpen" source license instead.