live composition of multiple sources including webcams, TV signals, movie filters, images, .txt files, particle generators
remotely controlled access (Vjoe)
scripting capabilities in Javascript
play back of flash vector animations
zero frame drop when looping movie clips
Emacs or Vi style console with hotkeys (S-lang)
accepts asynchronous controllers at the same time like MIDI and joystick
multithreaded video engine with low overhead
100% free software, under the GNU General Public License
modular C/C++ code and flexible API
utilizes multi-core processors (multi-threading)
Notably, the authors maintain that the license used, the GNU General Public License, is also a feature.