Name of the software: TeXMaker
Project/product Homepage: http://www.xm1math.net/texmaker/
Why we should include this into the repository, i.e. what does it do that the alternatives do not?: This is an easy-to-use LaTeX editor that incorporates spell-checking and can compile on-the-fly, useful for beginners to LaTeX and for doing complicated tasks with the language.
Is it open source?: Yes, GNU GPL v2
Source tarball: http://www.xm1math.net/texmaker/texmaker-5.0.2.tar.bz2
The Qt toolkit is required, can be compiled with gcc, clang and msvc.