This table is based on research by Team Vuo. It covers built-in features, not necessarily third-party add-ons. If you notice any inaccuracies, please send us a correction.

Visual programming (drag and drop)? Live coding (edit while running)? Debug mode (watch inner workings while running)? Number of graphics output windows
Vuo
Vuo has port popovers to show data in real time and a button to show events flowing through the composition
0, 1, or more
Isadora 1 to 6
Isadora supports up to 6 video output channels, limited by the number of displays the video card supports
Max 0, 1, or more
Processing No No 0, 1, or more
Pure Data No 0, 1, or more
Quartz Composer 1
TouchDesigner 1 or more
vvvv No 0, 1, or more