...
The Kafka project development ecosystem involves git (for version control), JIRA (for issue tracking) and either GitHub pull requests or Review Board (for reviewing code changes made by contributors). See below for more details.
Patch Review Tool
We are currently in the process of moving our contribution workflow to Github pull requests, so the patch review tool is slowly getting phased out. If you are still interested in using it, or learning more about it, you can find the instructions here.
...