Microsoft Announces Open-Source DocumentDB NoSQL Database

In a blog post dated for this past Thursday but only being made public on Sunday night, Microsoft issued an announcement open-sourcing their new NoSQL database... Where it gets weirder is that it's named DocumentDB. Amazon also has a database offering named DocumentDB albeit proprietary.

Microsoft announced the official release of DocumentDB as an open-source "document database platform" that powers Azure Cosmos DB for MongoDB and built on PostgreSQL. DocumentDB aims to be an open-source NoSQL datastore implemented atop PostgreSQL. Microsoft's DocumentDB is under the MIT license and they will welcome community contributions.

In 2025 it's not most strange that Microsoft is announcing an open-source database software solution but rather this time is its name... I find it very strange Microsoft naming this DocumentDB given Amazon DocumentDB already being in existence going back six years. Amazon DocumentDB is also a NoSQL database focused on MongoDB compatibility but proprietary software. I was even trying to find out if the Microsoft and Amazon wares had merged or similar but there appears to be no connection. And Microsoft Azure and Amazon AWS are direct competitors in the cloud space...

Microsoft's DocumentDB is described on its GitHub repository as:

"DocumentDB offers a native implementation of document-oriented NoSQL database, enabling seamless CRUD operations on BSON data types within a PostgreSQL framework. Powering vCore-based Azure Cosmos DB for MongoDB."

More details on the Microsoft DocumentDB via the open-source announcement on the Microsoft Open-Source Blog.