Slic3r is mainly a toolpath generator for 3D printers: it reads 3D models (STL, OBJ, AMF, 3MF) and it converts them into G-code instructions for 3D printers. But it does much more than that, see the features list below. Slic3r was born in 2011 within the RepRap community and thanks to its high configurability became the swiss-army knife for 3D printing. It served as a platform for experimenting several new ideas that later became technology standards, such as multiple extruders, brim, variable-height layers, per-object settings, modifiers, post-processing scripts, G-code macros and more. Despite being based on volunteer efforts, Slic3r is still pushing the boundaries of 3D printing.