I like to be up to date on new releases of the software I am using. Github has a number of ways to track user or project activity.

Repo releases

https://github.com/:owner/:repo/releases.atom

Repo commits

https://github.com/:owner/:repo/commits.atom

Private feed (You can find Subscribe to your news feed in dashboard page after login)

https://github.com/:user.private.atom?token=:secret

Repo tags

https://github.com/:user/:repo/tags.atom

User activity

https://github.com/:user.atom