Apple Shake is a node compositing program designed in the late 90’s by Ex-Sony Imageworks programmers Arnaud Hervas, Emmanuel Mogenet, Ron Brinkmann, Louis Cetorelli, and Dan Candelaand. The company, then named Nothing Real, was sold to Apple in 2001.
As a programmer, this app blew my mind when I first saw it in 1999. This was the first time I had seen a user interface completely made in OpenGL. Actually, the old Kaydara and Softimage UIs started as OpenGL but by the early 2000s had migrated to Windows-only/GDI/MFC.
It also had a dynamic property/inspector sheet on the lower right side. This made the software easier to use and learn as everything could be done in one window — no popups required.