Z:gnu-www-ja-categories--745e80-This diagram, originally by Ch/en

This diagram, originally by Chao-Kuei and updated by several others since, explains the different categories of software. It's available as a Scalable Vector Graphic and as an XFig document, under the terms of any of the GNU GPL v2 or later, the GNU FDL v1.2 or later, or the Creative Commons Attribution-Share Alike v2.0 or later.