Awesome Fabrication

Viewer

• 3dviewer.net - Online 3D Model Viewer.
• gcode-viewer - Web-based 3D viewer for GCode files.
• githubiverse - Template for Thingiverse like 3d-file hosting.
• JSModeler - JavaScript framework to create and visualize 3D models.
• thingiview.js - Javascript 3D Model Viewer (not updated since 2011).
• madeleine.js - 3D Model parser & renderer for STL files (ASCII and binary).
• va3c/viewer - 3D Model Viewer with Three.js (buggy).

Converter

• hmstl - Generate STL triangle meshes from grayscale height-map images.
• papercraft - Unfolding STL models to make laser cut patterns.
• plater.me - Auto-layout of STL files on print-bed.
• stltwalker - A scriptable interface for STL transformation and accumulation (written in C).

Host Software

• CuraEngine - C++ console application for 3D printing GCode generation.
• LaserWeb - Self hosted web interface for your laser or cnc mill.
• octoprint.org - Self hosted web interface for your 3D printer.
• Printrun - Pure Python 3d printing host software.
• Repetier - All in one 3D-printing software.

Slicer

• kisslicer - Fast easy-to-use cross-platform slicer.
• slic3r - G-code generator for 3D printers.