LaTeX

$\LaTeX$ is just amazing for every minimally complex document you need to do. The beauty of it is that you can focus on writing, while it makes all the magic of formatting for you in the background. It is true that LaTeX has a steeper learning curve than other What You See Is What You Get (WYSIWYG) alternatives, but I think, in a perfect world, it would make an enormous difference in productivity and easy of use for researchers, at the cost of five days to familiarize with it....