Besides the LaTeX base system, the LPPL is also used for most third-party LaTeX packages. Outside the LaTeX world it is rarely used.
The most unusual part of the LPPL – and equally the most controversial – used to be the 'filename clause': You must not distribute the modified file with the filename of the original file. This feature made some people deny that the LPPL is a free software license. In particular the Debian Linux community considered excluding LaTeX from its core distribution because of this.
However, version 1.3 of the LPPL has weakened this restriction. Now it is only necessary that modified components identify themselves "clearly and unambiguously" as modified versions, both in the source and also when called in some sort of interactive mode. A name change of the work is still recommended, however. This appeased the Debian community.
In order to provide project continuity in the case that the copyright holder no longer wishes to maintain the work, maintenance can be passed on to another (or from maintainer to maintainer). This can either be declared by the copyright holder or, in the event that the copyright holder is no longer able to be contacted, by the individual taking over maintenance, with a three month gap after their public intention to take over the maintenance. The modifying clause discussed above does not hold for the current maintainer of the work.
Unlike the works released under the LPPL, the LPPL itself is not freely modifiable. While copying and distribution is allowed, changing the text of the LPPL is not. However, it may be used as a model for other licenses provided they do not reference the LPPL.