GNU TeXmacs is one of the projets of SPI (Software in the Public Interest). You may make donations of money to TeXmacs via this organization, by noting on your check or e-mail for wire transfers that your money should go to the TeXmacs project. You may also make donations of equipment or services or donations through vendors. See the SPI website for how to donate. We also maintain a list of donators.
Please consider buying one or more copies of our book “The Jolly Writer”, which is an up-to-date guide for GNU TeXmacs. You may also ask your university library to order this book or invest a bit of your grant money to supply each of your co-authors with a copy.