However, many prominent Open Source projects that don't use GitHub have mirrors on GitHub, and as long as you star them, they appear in your GitHub profile if y

However, many prominent Open Source projects that don't use GitHub have mirrors on GitHub, and as long as you star them, they appear in your GitHub profile if you contributed to them using an email that is registered to your GitHub account. To give examples: - Git https://github.com/git/git https://github.com/git/git, - Linux https://github.com/torvalds/linux https://github.com/torvalds/linux, - LibreOffice https://github.com/LibreOffice/core https://github.com/LibreOffice/core, - Firefox https://github.com/mozilla/gecko-dev https://github.com/mozilla/gecko-dev