Microsoft’s DocumentDB Joins the Linux Foundation, Signaling a New Open-Source Era
The Linux Foundation has announced the induction of DocumentDB—a Microsoft-developed, open, document-oriented database—into its community. Licensed under MIT, the project was conceived as an alternative to MongoDB following its adoption of more restrictive licensing terms.
The emergence of DocumentDB traces back to 2018, when MongoDB abandoned its permissive license in favor of the Server Side Public License (SSPL). This license obliges cloud providers to disclose the source code of their services, sparking industry backlash and prompting companies to seek alternatives.
DocumentDB, in development since 2024, consists of PostgreSQL extensions that enable operations with BSON data models while maintaining compatibility with MongoDB. In essence, it fuses the relational robustness of Postgres with the flexibility of a NoSQL approach.
At its official release in January, Microsoft underscored the contrast with SSPL: the MIT license imposes no obligations on users. “There is complete freedom to use, fork, and distribute the project without any requirement to contribute changes back,” emphasized Abhinav Ramesh, Microsoft Azure Cosmos DB Manager.
This initiative also extends the momentum sparked in 2023 by the startup FerretDB, which introduced a PostgreSQL-based alternative to MongoDB. FerretDB called for the creation of a unified standard for document databases and, alongside the community, founded the Document Database Community.
FerretDB CEO Peter Farkas revealed in a LinkedIn post that MongoDB representatives had threatened legal action over product compatibility, culminating in a patent lawsuit in May 2025. According to him, today’s acceptance of DocumentDB by the Linux Foundation reaffirms that the community is indeed moving toward an open standard.
Microsoft Vice President Kirill Gavrylyuk highlighted that DocumentDB combines PostgreSQL’s reliability with the convenience of document storage. “Within just a few months, the project has gained strong community support. Joining the Linux Foundation reinforces our commitment to open governance and developer-first principles,” he stated.
In response, MongoDB argued that DocumentDB, being built on Postgres, inevitably inherits the constraints of relational architecture and cannot serve as a substitute for a “true” document database. Nonetheless, the company stressed that it continues to collaborate with Microsoft and supports the advancement of open approaches that foster resilient business models.
