Y&Y TeX is a TeX system developed for Windows; it was originally a proprietary product, but is now free software. http://tug.org/yandy/ has more information and background.
Y&Y TeX was donated to the TeX Users Group (http://tug.org) by Blenda Horn, one of Y&Y's founders. Per Blenda's wishes, TUG has now released the sources under the GNU GPL. Short documentation and other ancillary files are under an all-permissive license, since they could be useful to excerpt in other projects.
If you are interested in joining this project, please contact the project administrator(s) for write access.
These details are provided for information only. No information here is legal advice and should not be used as such.