Operating in realtime, Grabbo works with any video source, including broadcast television signals. Incoming video is analyzed and compared to stored video frames to compute MIDI values for output. Future versions of Grabbo will be able to send messages to any BeOS program, using BeOS inter-application messaging.

Grabbo analyzes images based on the orientation of objects, rather than position. Two different algorithms are currently provided: one outputs an index based on the closest matching image in a set of stored video frames. The other is a 3D interpolation scheme, which associates stored frames with points in 3D space, and computes a position between the points based on the similarity of the current video image to the keyframes. Using BeOS inter-application messages from Grabbo, the current 3D position is displayed using OpenGL by a companion application, 3dReceiver.

Grabbo requires a BeOS-supported video capture card, which currently includes most cards using a Bt848 chip, such as the Hauppauge WinTV. Grabbo also requires a video display card which supports BeOS BDirectWindow, which allows 30fps display of incoming video. External MIDI hardware is not required, but is needed to realize Grabbo's full potential as a MIDI controller: Grabbo can use the BeOS built-in synthesizer.