Frets on Fire X (https://fofix.github.io/ https://fofix.github.io/) is one. And I guess the original Frets on Fire. Edit: Clone Hero looks more recent/active.

Frets on Fire X (https://fofix.github.io/ https://fofix.github.io/) is one. And I guess the original Frets on Fire. Edit: Clone Hero looks more recent/active. However I'm not sure it's open source. https://clonehero.net https://clonehero.net