A remark overheard at the end of a math lecture, when the students were complaining about having to use different programming languages in different math classes (R, Octave, Python): “Everything is money.” This was intended as an explanation for why essential free-software libraries for certain algorithms were not available in some of these programming languages, ruling those languages out for classes that needed to use those algorithms.
This struck me as profoundly short-sighted and unaware of the history of free-software development, particularly coming from a professor who shall not be named but who can trace their academic lineage back to Lagrange. When Euler and Lagrange were inventing the variational calculus in 1754 to 1756, Euler was indeed being paid — he was the director of mathematics at the Prussian Academy of Sciences. But spending some of his professor time on reading letters from Lagrange was entirely his own decision — not only did the providers of funding not know that Euler was doing this, but under the basic norms of Prussian academic freedom later codified by Humboldt, they did not have the right to know or to veto it. Moreover, Lagrange was not being paid for this; he did get a position as Sostituto del Maestro di Matematica for the Piedmontese army in 1755, but there he was being paid to teach calculus and ballistics to military artillery engineers.
The variational calculus wasn’t published until 1762, at which point it was published by the Turin Society (Societas Privata Taurinensis), which Lagrange established with his students in 1757, and which today is the Accademia delle Scienze di Torino. It was initially established as a private club, but before the publication of the variational calculus, it had gained royal patronage from Victor-Amadeus in 1759, making it the Royal Turin Academy of Sciences (Société Royale des Sciences de Turin).
Much of the history of mathematics, academia in general, and free software is like this. If you want to know why a theory was developed or why a book or free-software library was written, it is only minimally informative to investigate who was paying for it and what they wanted to fund. Instead you should look for what interested the individual people who developed or wrote it, what other scholars they were in touch with, and what ideas they were influenced by.
Sometimes the absence of free software or research can be explained by funding. Snapshots in free-software filesystems don’t exist because NetApp funded patents to stop them during many years. High-quality free-software mixed-integer linear programming solvers don’t exist because researchers use CPLEX, Gurobi, Xpress, or SCIP — see Some notes on the landscape of linear optimization software and applications for the whole sad story. There’s no decent free-software spreadsheet for Android because people just use Google Sheets. Little public-domain research exists on isotopic enrichment because the US and Israel have funded wide-ranging efforts to prevent it, to the point of releasing industrial-sabotage viruses into the wild and assassinating researchers.
Wikipedia, of course, is the first place any student of mathematics goes to learn about any mathematical concept. Wikipedia is written and edited by people who do not get paid, except in a minority of cases usually considered vandalism.
So, not everything is money, I think.