Who am I? Huh...
I'm doing a PhD in mathematics, working on non-standard analysis, linear logic and proof theory. I have to edit some amazingly intrincated diagrams from time to time, and I started to learn Tcl/Tk (in mid-98) just because it seemed to be the right tool to write a diagram editor; I quickly found that it's a lot more than that, and became addicted. Later I became addicted to Expect and mktclapp too; I'm trying to pack mktclapp for Debian, but I'm stuck with manpage-writing.
The best thing I've ever done with computers is this eev.el thing ([L1 ]), that lets me embed hyperlinks and chunks of shell/tcl/TeX/etc code inside plain text files ([L2 ]). I think it is a definitive (!) argument to make people use Emacs instead of using text editors. See the "eev manifesto" at [L3 ].
How to edit Wikit pages with Emacs