LaTeX is a document preparation system for high-quality typesetting. You can use LaTeX for any form of publishing -- and I do -- but it does tend to be used for scientific publications of medium length and upwards, because this is where its biggest strengths lie.

Using LaTeX is more comparable to writing HTML or XML than to using a word processor; instead of directly editing your document on a WYSIWYG display, you edit a source file which is then compiled into another format for viewing and printing. Generally, this format is LaTeX's own DVI (DeVice Independent file), but postscript and PDF are easily produced too.

## Why would I want to use it?

There are a number of advantages to using LaTeX. I will look at some of the main ones.

Mathematics
This is regularly seen as LaTeX's greatest strength. Its ability to typeset really good-looking complex mathematical formulae is beyond compare.
Separation of style and content
This one comes up a lot, but its effect is often underestimated. When you first learn to use LaTeX, you have to learn all these squiggly characters and funny commands and it looks like typing anything is going to be a real hassle. Once you actually get down and start typing something for real, though, you find that you can do so in LaTeX much easier and faster than in a word processor. This is because you can forget about style. LaTeX takes care of much of the formatting, and the rest you can play with later but once you're in flow, you can just keep typing; no need to worry about line-breaks, page-breaks, fonts and whatever.
LaTeX produced documents look really good
Seriously. You can slave away on Microsoft Word or Openoffice Writer for as long as you want and your document will not look as good as the report I just knocked out in LaTeX.
Absolute stability
LaTeX has been around for decades. TeX, the underlying technology, has been around for even longer. In fact, Donald K. Knuth halted all development on TeX a long time ago because there's nothing left to do. The are no bugs left! LaTeX may not always do what you think it should, but I have never ever known it to do something it actually shouldn't.
Classes and Packages
Want to do a presentation with transition effects and everything, like Powerpoint can? Have a look at the Prosper class. Writing a letter? Use the letter class. Reports, CVs, books, essays? Need to use Matrices, draw chemical diagrams? Music notation? All these things are done easily with the huge amounts of extra classes and packages that may be used with LaTeX. CTAN is a website (ctan.org) dedicated to the storage of many of these.

## How to create a LaTeX document

LaTeX source files are plain text documents, so you'll want to whip out your favourite text editor. Vi and Emacs have good modes for editing such files but anything that can read & write plain ASCII will do. Yep, even notepad.

All LaTeX files begin with a document class command, and the main the main stuff is in a document environment. The best way to explain this is to look at a simple example:

\documentclass[a4paper]{article}
\begin{document}
\section{The first}
Hello, there.  Here's some text.  Just like HTML, extra
spaces and carriage returns are ignored, LaTeX performs
its own formatting when it compiles.

New paragraphs are made by a double carriage return, like
that.

\section{Another}
Things like \emph{emphasis} and \textbf{bold text} is
very easy. How about some lists?

\begin{itemize}
\item This is an item in a list
\item So's this.  They'll have bullet points
\item Dum, de, dum.
\end{itemize}

Or a numbered list...

\begin{enumerate}
\item This is an item in a numbered list
\item You can define your own numbering systems
\item And they nest very easily
\end{enumerate}

\end{document}

Save that file as foo.tex or something similar, and run it through LaTeX like this:

latex foo.tex

You will then find a few extra files have been created. The important one is foo.dvi. Open this with a dvi viewer like xdvi or kdvi, or, if you like, you can turn it to postscript with dvips and view that.

You should find it looks something like this (but prettier):

## 1. The First

Hello, there. Here's some text. Just like HTML, extra spaces and carriage returns are ignored, LaTeX performs its own formatting when it compiles.
New paragraphs are made by a double carriage return, like that.

## 2. Another

Things like emphasis and bold text is very easy. How about some lists?

• This is an item in a list
• So's this. They'll have bullet points
• Dum, de, dum.

Or a numbered list...

1. This is an item in a numbered list
2. You can define your own numbering systems
3. And they nest very easily

This is obviously, only a simple document, but it gives you a taste of the LaTeX way of doing things. The online help is a great resource to help you move on from here. It's on longer files that LaTeX really begins to shine. Pages and sections (and subsections, and subsubsections) are automatically numbered. It will build tables of contents for you and there's environments for tables and pictures. All the time, LaTeX works hard in the background to lay out your pages in the best way it can without all the formatting getting in the way of your writing.

## Anything else?

Well, yes. There's latex2html which will turn your documents into web pages, pdflatex which produces great PDF files and, of course, thousands of packages and classes on CTAN to help you with anything you may want to do.

Once you've started using LaTeX, you'll begin to hate word processors, seriously. Your printed work will look far superior to those of lesser Word-using mortals and attractive members of the opposite sex will fall at your feet.

Versions of LaTeX is available for almost any computer system you may be using. All flavours of Unix and Linux, MacOS (including OS X), Windows, QNX, VMS the list is almost endless. If you haven't already got it installed -- if you're using Linux, you probably have -- go and download one now.