Open Source Simplify3D Alternatives

Cura aims to be a end solution for personal 3D printing with RepRap based machines. It is tuned toward the Ultimaker, but can be used on any RepRap based design.

PrusaSlicer (formerly known as Slic3r Prusa Edition or Slic3r PE) is our own in-house developed slicer software based on the open-source project Slic3r. It's open-source and you can get it in our Drivers & Apps Package.

MatterControl is a free, open source app that lets you organize and manage your 3D prints. It's designed to help you get the most out of your 3D printer - making it easy to track, preview, and print your 3D parts.

STL-to-GCODE translator for RepRap printers.

SuperSlicer takes 3D models (STL, OBJ, AMF) and converts them into G-code instructions for FFF printers or PNG layers for mSLA 3D printers. It's compatible with any modern printer based on the RepRap toolchain which is running a firmware based on Marlin, Prusa, Klipper, etc.

Printrun is a full suite of host interfaces for 3D printers and CNC, consisting of:

This is the software that will drive your MakerBot Replicator, Thing-O-Matic, CupCake CNC, RepRap machine, or generic CNC machine. You can give it a GCode or STL file to process, and it takes it from there.

SuperSkein is a first-order model slicer that runs in Processing. It's pretty basic still, but since it's object oriented and in Processing (which could be quickly ported to C) it should be easy for the community to hack and improve.