While at the latest ruby on rails conf I saw a demo on a fellow programmers macbook pro of a GUI developer tool that lets you route audio video through filters and what-not and create screen savers and little apps using what looked like encapsulated program modules. These modules seemed to represent system native functions like video and audio inputs etc. All he had to do was route these modules together (drag drop / arrow connectors like the reaktor music program by native instruments) and export it all as a screensaver. Wondering if anyone knows what this tool is called? I'm drawing a complete blank. thanks much!