So, I've been working on my open source Classroom Control System this month, and I've just started to write the installers. If you are familiar with NetOp's School6 software, you know how powerful a classroom control system can be.
My classroom control system will allow teachers to see what student computers are on and apply actions to any of them. Teachers can rearrange the internal frames that represent the student computers and save the layout as he / she sees fit (useful to easily tell what computer you are controlling). The teacher can remote control a student's computer via the CCS's interface. That particular function uses the free program RealVNC. Just think if the teacher's computer is hooked to a projector. The teacher can ask a student to perform a task for the class, or they can answer the question that the student had for the class. If the room doesn't have a projector, the teacher can simply use the Broadcast Screen function to broadcast his / her screen to any or all of the student computers.
But there's more. The teacher can set a whitelist or blacklist for both programs and websites and save the policies under his / her particular profile. You can also do things like Turn Off Monitor, Turn Off Machine, Empty Recycle Bin, Mute Volume, Unmute Volume, and set an open lab.
I'll make sure to put up a link when I'm finally done.