Is Identity used in any open source project?

Hi there!
I am currently trying to use Identity for some projects of my own but I seem to get confused when implementing all the functions it can provide.
I wish there were some production ready project so I could see and compare how people are using Identity so I can see and give myself an idea to how I could use it for my projects.

Aside from a project that uses Identity. Any resource of guidance into how to use Identity would be highly appreciated.

Thank you for your time!