Syphon Virtual screen is a tool to share video output in applications that can go full-screen but are not yet Syphon-enabled. The framebuffer resides in CPU memory, so maybe it could not be the best solution for heavy video processing: every frame has to be uploaded to the GPU RAM to be published on a syphon server, and this is a (relatively) slow operation. The best would be having native Syphon support in the application you target of course, but if you're here it means you can go that way.
A small portion of drive space on your new My Passport or My Book hard drive.
SX "Virtual Link" allows applications to communicate across the network.
Easy to use employee time clock software.
On-screen keyboard program for Mac OS X.
Virtual MIDI Keyboard displays a musical keyboard on the screen.