The LaTeX3 project
LaTeX is a typesetting system which is widely used in the publishing industry and in academic circles for producing a wide range of document types. The LaTeX3 project is a long-term research project to develop the next version of the LaTeX typesetting system.
The LaTeX3 project accepts donations by credit card via the TeX Users Group. The donation page is here https://www.tug.org/donate/dev.html.