RepRap stands for Replicating Rapid Prototype. RepRaps can print at least some part of themselves to make a new printer. My guess is that if you add up all the RepRaps on that list they will outnumber any of the commercial printers.

Prusa comes from Josep Prusa. He is a Czech engineer who invented the Prusa Mendel, Prusa i2 and Prusa i3. What is noteworthy about him is that his inventions are truly open source and kits of them are sold by many online vendors. He really stands by this and was very disappointed and vocal about it when Makerbot went closed source.

Printrbot was also a RepRap when they did their first Kickstarter. Brook found out very quickly though that it is a nightmare to mass produce $800,000 worth of printed printers.

Cheers,

KDog