cflow has one maintainer who is also the developer for the project. It is still currently an active project which uses a mailing list for notifying of bug reports and suggestions.
I had a look at the most recent patch from November 2016 regarding inverted trees missing the static function calls in the flow chart list. The review process was seemingly quick and this method of review (mailing list, contrary to the workflow directly within GitHub) worked well in this case as the maintainer was able to review and apply the change successfully within a couple of weeks. Although the workflow is not done directly on GitHub, the maintainer has made the project available from a Git repository as well as in CVS for contributors to work on the code. The project’s official website also includes some well documented usage for Git.
Using GIT at Savannah: http://savannah.gnu.org/maintenance/UsingGit/
For the cadvisor open source GitHub project, I had a look at the review process for the ‘Build & test cAdvisor with go 1.7.1 #1508’ pull request from October 19, 2016. It addresses an issue that was opened August 22 of that year, regarding the release of cAdvisor v0.24 with go version 1.7. Responses to the request were made the very same day by active participants in the project. It was then reviewed by one of the maintainers on November 2, 2016, a few things were discussed regarding builds on a specific environment, and the pull request was finally merged on December 5, 2016.
Github is a great way for developers to share and contribute their ideas and suggestions to the open source community. The review process for pull requests and merging those changes is safe because it requires all necessary tests to pass successfully before being able to merge them into the project. I also found that although GitHub is the most used version control system for open source projects, the use of mailing lists (i.e. the cflow project), can work just as well if the scope of the project is not too large and there is only one or a few active maintainers.