[Pinkertron]

Another powerful program along the same lines is touch designer https://www.derivative.ca

It's an offshoot of Houdini. It is exceptional at working with external hardware controllers and networking.

[CyberDildonics]

Really have to give it to touch designer, it is a fantastic piece of software that seems underrated with the current state of input devices and graphics power.

[sdwisely]

also worth mentioning:

http://vuo.org - intended as a replacement to quartz composer and cross platform later on.

http://www.bigfug.com/software/fugio/ - cross platform and came out this week.

"Fugio is an open visual programming application with support for Oculus Rift, timeline based media playback, OpenGL, OSC, MIDI, Arduino, and much more!"