Open-source

statistics:

• https://coderstats.net/github/#apache
• https://www.somsubhra.com/github-release-stats/?username=apache&repository=cassandea

software

• https://rocketmq.apache.org/docs/faq/
• https://github.com/apache/pulsar
• https://github.com/apache/trafodion

protocols:

• JDBC
  • https://calcite.apache.org/avatica/ - Avatica is a framework for building database drivers.