TeX and LaTeX are widely used in Computer Science. What other academic disciplines or professionals use it?
I'm a mechanical engineer working in materials science / materials processing.
I had lots of experience (from quite good to extremely bad) with
Some of my colleagues (mostly engineers and chemists) also use(d) LaTeX for typesetting their thesis, but many that I know use
Some "statistical" data of people
We actually have a colloquium course at my college in which one is required to use LaTeX. It has to be taken once for all math minors, twice for all math majors. The entire object of the course is to learn technical, mathematical writing, for which LaTeX is considered required.