Just to clarify, I was never a developer of Passbolt. I think they based their repository off of CakePHP (which I do maintain) and inherited all the commit history that way.
With this type of display, you can quickly see who is contributing on an active basis, and for how long. A good example would be the vscode repository.
Indeed GitHub's contributors graphs gave me the impression that https://github.com/markstory worked on passbolt. Isn't that is what they are supposed to?
Wish you all the best with your enhanced developer insights.
Yes the repository was forked from CakePHP v2, before the framework was moved as a composer dependency, so v2 contributors are shown as Passbolt contributors.