Prusa3D - Open-Source 3D printers by Josef Prusa. Prusa Research is a 3D printing company based in Prague, Czech Republic. It was founded by Josef Prusa, one of the core developers of the Open Source project RepRap, in 2012 as a one-man startup and grows to a 400+ team now. His open-sourced Prusa i3 design is according to 3DHubs the most used 3D printer in the world. We are shipping more than 6000 Original Prusa i3 printers per month to over 160 countries directly from Prague. Our MK3/S printer is the best 3D printer for 2018 and 2019 according to MAKE: Magazine US and the best FFF printer according to 3D Printing Industry Awards.