You can check more in those sources: - https://techcrunch.com/2019/01/09/aws-gives-open-source-the-middle-finger/ https://techcrunch.com/2019/01/09/aws-gives-op

You can check more in those sources: - https://techcrunch.com/2019/01/09/aws-gives-open-source-the-middle-finger/ https://techcrunch.com/2019/01/09/aws-gives-open-source-the-... - https://news.ycombinator.com/item?id=18871483 https://news.ycombinator.com/item?id=18871483 - https://www.enterprisedb.com/blog/documentdb-really-postgresql https://www.enterprisedb.com/blog/documentdb-really-postgres... TLDR: AWS didn't want to pay for licenses and rolled out their own thing.