Open Source does not mean that the use of the code is allowed without any restriction: The use is subject to conditions which are formulated by the author (copyright holder) in the form of a license.
Recently, Bitsea observed some Open Source projects maintained by commercial companies have changed their license conditions from a rather business friendly i.e. with very few (if any) obligations, to more restrictive licenses in newer versions of the software. Elastic (a real-time search server based on Apache Lucene), Redis (an in-memory database), MongoDB (database) or Grafana (graphical representation of data) should be mentioned here. All of them adapted their licensing models to more restrictive licenses. The reasons for that appear to be similar: to force current users, especially non-paying businesses, to purchase commercial licenses of those OSS products.
These changes have generated a lot of friction between existing users of the software and current OSS maintainers.
Read the full story by Dr. Andreas Kotulla, Founder and CEO of Bitsea, here.