LibreCAD is a free, open source 2D CAD application for Windows, OS X, and Linux. Blender is a free, open source 3D computer graphics software used to create 3D models, animation, and video games. It comes with a GPL license, allowing users to share, modify, and distribute the application. MeshLab is an open source, portable, and extensible system to process and edit unstructured 3D triangular meshes.

The following are the links to install LibreCAD in Windows, Linux, and OS X:

• Visit http://librecad.org/cms/home.html to download LibreCAD
• Visit http://librecad.org/cms/home/from-source/linux.html to build LibreCAD from source
• Visit http://librecad.org/cms/home/installation/linux.html to install LibreCAD in Debian/Ubuntu
• Visit http://librecad.org/cms/home/installation/rpm-packages.html to install LibreCAD in Fedora
• Visit http://librecad.org/cms/home/installation/osx.html to install LibreCAD in OS X
• Visit http://librecad.org/cms/home/installation/windows.html to install LibreCAD in Windows