Name: GNU TeXmacs
GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. It is especially enjoyable to edit mathematical formulas within TeXmacs.
I, a college student, find it really helpful when writing experiment reports. And I have not found any other comparable solution.
License: GPL 3
Link to latest stable source release: http://www.texmacs.org/Download/ftp/tmftp/source/TeXmacs-1.99.5-src.tar.gz
Suggestion for packaging TeXmacs http://www.texmacs.org/tmweb/download/packaging.en.html