RBA was written in LaTeX, as will all the texts on FMTo, for a number of reasons:

What follows is mostly obsolete and, by now, the (much simpler) way to install LaTeX is just to go to TeXLive. I will try to elaborate in the not too distant future.

August 27, 2011

Chances are, you need to install LaTeX but, unfortunately, it is a bit more complicated than installing a word-processor and requires two pieces of software, an editor and a TeX distribution. And of course, the installation will depend on what OS you are running.
You are now done and your installation should be able to handle basic LaTeX files.

is a regular Mac application and it is the only application you will be dealing with; it is both a text editor and a typesetter, the latter meaning only that, when you want, it passes the source file to gwTeX for the LaTeX source to be processed by pdflatex and then Mac OS X (> 10.3) into a pdf output file. TeXShop should be capable of immediately opening any basic LaTeX source file which you can then typeset by clicking on the Typeset button at the top of the LaTeX source file. Once TeXShop has typeset a LaTeX source file, TeXShop displays the pdf output file which you can then print by clicking on the Print button at the top of the pdf output file or like any other Mac OS X file. One very nice feature of TeXShop, by the way, is that once TeXShop has typeset a LaTeX source file, it lets you go from any point in either the LaTeX source file or the pdf output file to the corresponding point in the other file.

In general, though, LaTeX files involve and require supplementary style sheets and RBA is no exception in that regard. The necessary style sheets are in the Complete RBA Source (216.6MB), which is merely zipped to hold all the files together You can also get Complete RBA Source Compressed (16.5MB).

You need to place these style sheets in:
Users > Yourself > Library > texmf > latex

*  Minimal that it is, all of RBA was done with this installation along with just a few supplementary style sheets … but with much help.