Below is a list of licenses of various TeX-related software as recorded in The TeX Catalogue as maintained by Graham Williams. In all cases, please check the software's license before using the software. General information about categories of licenses is avaiable from GNU.
The license conditions determine whether the software is located on CTAN under the normal hierarchy or in the nonfree hierarchy. In this way, redistributors of TeX and family can be surer of the legal situation. The simple criteria is that any software not satisfying the Debian Free Software Guidelines will be recognised as nonfree software.
Free software satisfies the criteria contained in the Debian Free Software Guidelines. This software can be freely used, modified (hence source must be available), and distributed (e.g. on distributions like TeXLive, teTeX, and MikTeX). It is generally copyrighted to legally protect it. Users are generally given an explicit license to copy, distribute, and/or modify the software. Authors of free software may invite users to make monetary donations if they wish, but can not oblige them to do so, or else the software becomes nonfree. Free software may rely on nonfree software for extra functionality, but provides useful functionality without that nonfree software.
While one category would be sufficient (dfsg) we identify the common subcategories that satisfy the DFSG:
dfsg | Debian Free Software Guidelines | |
gpl | GNU General Public License | |
lgpl | GNU Library General Public License | |
lppl | LaTeX Project Public License | |
pd | Public Domain |
Nonfree software has restrictions on it that prohibit its free distribution. Software in this category can not be included in distributions except, in general, by special permission or by payment of a fee. This software does not satisfy the Debian Free Software Guidelines On CTAN this software is to be found in the nonfree hierarchy.
unknown | ||
nocommercial | ||
nosell | ||
nosource | ||
shareware | ||
other | usually commercial |