TeX
I am installing TeX on my PowerBook. I bought The TeX Book 
many years ago, and several years ago, I bought a CD containing several TeX distributions, but I never got them to install properly. Now I think I’m almost done with a TeX installation. I’m excited!
TeX is a typesetting program invented by Donald E. Knuth, who wrote some books called The Art of Computer Programming (volumes 1, 2, and 3). Knuth is a pioneer of theoretical computer science. TeX can be used to typeset mathematics and physics.
Let’s see, how did I get to where I am tonight? For a start, I am following the instructions I found on http://www.esm.psu.edu/mac-tex/. I found that link in the help pages for Ulysses, a text editor for creative writers. I heard about Ulysses because I surfed to http://daringfireball.net/, a nice website I’ve visited several times before. (Daring Fireball is the website of John Gruber, whose Smarty Pants is one of my favorite plugins for Movable Type.) I visited Daring Fireball tonight because I had been playing around with Alexa (http://www.alexa.com/), and when I looked up the traffic rankings of http://www.meyerweb.com/, no http://www.dooce.com/, Daring Fireball was last in the list “People who visit this page also visit:” for dooce.com.
And it (TeX) works. The fifty-cent description:
TeXShop provides a GUI for teTeX, a version of the actual TeX program (which is unabashedly a command-line driven program).