HEATKEYS

Inkscape is a Vector Graphics Editor, similar to Adobe Illustrator, that strives to be SVG Compliant, open source, responsive and extensible.

The goal of the LaTeXDraw project is the development of a graphical PSTricks editor or generator for latex. It is open-source and free. It works on Linux, Windows, Mac OS, ... if you have Java

Draw, share and collaborate on online diagrams. Easy web flow chart, network diagram, mockup, wireframe, UML diagrams like Class, Sequence, & data flow and process flow diagrams. Creately - free web-based software for online diagram software

Edraw is a powerful yet easy-to-use program for creating flowcharts, organizational charts, network diagrams, business presentations, building plans, mind mapping and lots more.

MathWorks is the world’s leading developer of technical computing software for engineers and scientists in industry, government, and education