Free diagramming software

Inkscape is a free and open-source software vector graphics editor released under a GNU General Public License (GPL) 2.0 or later. It is used for both artistic and technical illustrations such as cartoons, clip art, logos, typography, diagrams, and flowcharts. It uses vector graphics to allow for sharp printouts and renderings at unlimited resolution and is not bound to a fixed number of pixels like raster graphics.

diagramming software

thumb|250px|right|A red–black tree plotted by Graphviz thumb|250px|right|Undirected graph showing adjacency of the 48 contiguous United States thumb|250x250px|A visualization of a JavaScript life cycle made by using Graphviz Graphviz (short for Graph Visualization Software) is a package of open-source tools initiated by AT&T Labs Research for drawing graphs (as in nodes and edges, not as in bar charts) specified in DOT language scripts having the file name extension "gv". It also provides libraries for software applications to use the tools. Graphviz is free software licensed under the Eclipse

Xfig is a free and open-source vector graphics editor which runs under the X Window System on most UNIX-compatible platforms.

open-source, cross-platform illustration program