Software Discuss 3D Printing Software mainly slicers and firmware. For CAD software see discussion <a href="https://www.3dhubs.com/talk/c/cad/cad-software">here</a>.
3D Printers Discuss everything related to 3D Printers. Including performance, troubleshooting, hacking/upgrading of 3D Printers etc.
Materials Discuss 3D Printing materials, from filaments to resins, from powders to pellets. Material properties, printer settings and new developments.