What the heck is Latex?

This document attempts to explain what Latex is, in under five minutes.

Latex is a document preparation system

You use Latex to create documents for others to read. In that respect it is similar to Microsoft Word. But the similarities end there.

Document preparation with Latex typically consists of using a text editor (such as Emacs, vi, or even Notepad) to edit a Latex source file, which has the extension .tex, and then running the latex program to convert the source file to a document interchange format such as Postscript or PDF. Once the document is in a document interchange format, it can be previewed on the screen, sent to others, printed, etc.

What is up with the name "Latex"?

The name is (in my opinion) the worst part. It is too easily confused with latex, a synthetic rubber-like substance, and it seems elitist to many people. But try to forgive the name; it was created by Computer Scientists like me, and we're terrible at naming things.

Pronounciation:   I usually pronounce it "LAY-tek", though some pronounce it "LAH-tek". In any case, the second syllable is not pronounced "teks".

Typography:   In an obnoxious combination of captialization, font sizing, and baseline offsetting, Latex is often (and officially) written LATEX. Actually, the HTML doesn't really do it justice, so I made the following image using Latex itself:

LaTeX Logo

Even by writing "Latex" instead of "LaTeX" or "LATEX" I'm violating the "recommended practice". But the other forms are just too annoying. The reason for this bizarre arrangement of letters is in part to distinguish it from the aforementioned rubber-like substance, but mostly to show off what is possible in Latex (encouraging the perception of elitism).

Etymology (word origin):   Donald Knuth created "Tex" ("TEX"), the three letters actually being uppercase Greek tau, epsilon and chi. This Greek "tex" is the root of English words like "technical" and "technique". Later, Leslie Lamport built "Latex" on top of Tex, prepending the "La" presumably to reflect his name.

Markup versus WYSIWYG

To someone familiar with MS Word or the like, the most radical aspect of Latex is that you do not (necessarily) interact with a graphical user interface (GUI), and you do not immediately see how your document will be typeset.

Consider a typical WYSIWYG ("what you see is what you get") word processor, such as Open Office, shown in the screenshot below:

OpenOffice screenshot
In such a program, the GUI always shows what the final printed copy will look like, including formatting, etc. The GUI further contains a bunch of buttons (etc.) that can be used to apply formatting.

In contrast, the usual mode of interaction with Latex is via a text editor. The screenshot below shows fox.tex being edited in Emacs:

Emacs screenshot
Here, we just see the plain text input file, plus the markup commands that apply formatting. This is similar to HTML. Actually, Emacs does show a little more than the plain text, by using different colors for different elements of the Latex input file, and even using boldface for the text that follows the boldface markup command "\bf".

When you want to see how the document will actually look when printed, you invoke the latex program to generate (typically) Postscript, and then view that with a previewer program such as gv. Below is a screenshot of using gv to look at the output of fox.tex:

gv screenshot

Postscript is a good interchange format on Unix systems, but in the Windows world, PDF is much better. I usually convert Postscript to PDF using ps2pdf. You can also use a specialized version of latex called pdfTeX. The produces output that works better with onscreen previewers; they should produce identical printed output. Both are typically included with Latex distributions.

What is good about Latex?

Why would anyone use Latex? Here are some good points:

What is bad about Latex?

So why would anyone not use Latex?

How do I get started?

If you want to get started using Latex, here is what I recommend:

Related Links

Here are some related sites that may be of interest:

Valid HTML 4.01!