Docky
Open Source
Docky is a full fledged dock application that makes opening common applications and managing windows easier and quicker.
Avant Window Navigator
Open Source
Avant Window Navigator (AWN or Awn) is a dock-like bar for Linux, which sits on an edge of a user's screen and tracks open windows.
Cairo-Dock
Open Source
Cairo-Dock is a desktop interface that takes the shape of docks, desklets, panel, etc.
Compare Circle Dock with alternatives
Compare Cairo-Dock and Circle Dock and decide which is most suitable for you.
Compare Avant Window Navigator and Circle Dock and decide which is most suitable for you.