I want to add perspective. TeXmacs provides unique functions on top of a fairly complete 'normal word processor'. Openoffice had at some point >100 paid programmers working on it [0] - for many years, Joris was able to provide most of the functionality, and then some more (remember TeXmacs is a typesetter), while essentially working alone and building a successful career as a mathematician. That he wrote extensive documentation along the way, always accessible from the program itself, available on the web (pdf, html) and increasingly complemented by discoverable, self-documenting interfaces, makes this feat even more impressive. TeXmacs is not one of those programs where somebody is having fun coding while neglecting documentation and expecting somebody to take care of it. Much to the contrary, TeXmacs is well-documented since the beginning, and all this documentation was always under free licenses.
Now, the conversation was rather concretely about Joris' recent book[1]. The book is a work of love to typography and scientific document creation, and gives some additional perspectives on TeXmacs, but while I enjoy reading it and learn new things, I recognise that most (all?) the practical information inside it was available in various ways already. I do welcome the prospect of the book being liberated in the future, but I also feel an overwhelming gratitude to Joris for all the work that he has done above and beyond what he needed for his own purposes -- in adapting the program and explaining it -- all in free terms.
We could have an abstract discussion and conclude that a restrictive copyright book is less desirable than a free book. This is also my viewpoint, and I wish that we all will buy that free edition just the same if/when it comes out, and also donate to the project [2]. But it would be ungrateful to forget that in this particular case, the author already made a long, consistent end exhaustive effort over years to document the program under a free license.
Best regards,
Álvaro.
StarDivision had 200 employees when sold to Sun in 1999; I later read this 100 figure about the Sun time but I haven been able to find a citation. Libreoffice started with >200 contributions, today they are countless.