Another one that works great but is little known is Guitarrero. It has a website[1] and it is open-source as well[2]. When I still played Guitar Hero clones, it was the one with the best performances.

[1] http://playguitarrero.online.fr/index.php?en

[2] https://github.com/fontaromain/Guitarrero

Frets on Fire X (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

Clone Hero appears to be the most active. Made in Unity, nice.

Rocksmith is good too, but more serious