Xmind - Xmind is a brainstorming and mind mapping application.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.
FreeCAD - An open-source parametric 3D modeler