# What are TeX and LaTeX?

I'm surprised no one else has asked this question. It's not explained very well in the FAQ or site descriptions either.

I know many of you will think "LMGTFY", "RTFM", or "ask wikipedia", but I'd rather get the answer straight from the experts.

I'm so green I don't even know what to tag this question.

• what is it?
• what is it used for?
• who uses it?
• what is it in alternative to?
• how widespread is its use?
• does the average user type the language in as plain text or are there WYSIWYG tools?

And finally, a nice fun subjective bit to end things on a sour note. I guess this leads a bit back to the question regarding what TeX is the alternative to.

Is it a worthwhile technology to invest time in learning as a programmer/technology junkie who hates word processing apps with a passion? I'd rather write a wiki page than a letter in Word. But I don't know if that means I should switch from plain text to TeX or if that's like using a bazooka when all i need is a hammer?

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You could have a look at: Why should I use LaTeX? and What is TeX used for?. –  Stefan Kottwitz Dec 9 '10 at 12:59
Had the same doubt was afraid to ask ;). Excellently presented question. –  Trufa Dec 9 '10 at 13:05
At this point, it might not even be necessary to "learn" that much latex. This is dependant on what you need TeX for-- if it's academic, go with latex, if you just need some general MS Word replacement, go with ConTeXt. Further, you could go with markdown (and pandoc to convert it to latex, context, docbook, etc etc). If you're an emacs user, you can use org-mode (roughly the same idea as markdown), or you could use rst. All of these are easier to learn than tex (markdown is dead simple). Again, it just depends on your publishing needs. –  Mica Dec 9 '10 at 18:41
@Mica: I'm a vim user... any tools for that? –  Robert S Ciaccio Dec 9 '10 at 18:46
Vim markdown: plasticboy.com/markdown-vim-mode vim context: wiki.contextgarden.net/Vim vim latex: vim-latex.sourceforge.net –  Mica Dec 9 '10 at 20:29

First, Mike's answer is quite good. I will mostly expand on it and provide more details.

### TeX

TeX is a language (a full programming language, actually) for typesetting documents. It originally output to a format called DVI which could then be converted to PostScript, PDF, etc.; more recent versions can output directly to PDF. You write a document with TeX instructions in it, and the TeX system will convert it into printable material.

TeX is used for a wide variety of documents, particularly in science and academia. Most people use it for things that other people would likely use Word for; however, the quality of its results are more on a par with InDesign or other major document layout packages, far superior what word processors generally yield. Designing specialized or ad-hoc document formats such as brochures, however, is probably easier with InDesign or QuarkXPress (although it is not impossible to do so in TeX/LaTeX).

TeX itself is quite low-level.

### LaTeX

LaTeX is a macro package written in and for TeX that provides commands and defaults for writing larger documents at a higher level, taking care of things like sectioning, tables of contents, etc. In my experience, most TeX users do not write low-level TeX directly, but rather use LaTeX. LaTeX is not the only such package, though; ConTeXt is another macro package with a different design philosophy, but it sits at a similar level to LaTeX.

### Usage

TeX and LaTeX are very widespread in some portions of academia, such as mathematics and computer science, due to its superb support for mathematical formulas. I have also heard that it is popular in some other disciplines as well, such as linguistics.

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I'd say, its typesetting quality is comparable to Indesign, but its strengths and capabilities are so completely unlike Indesign that "on a par with" is positively misleading. Graphics designers producing things like trifold leaflets overwhelmingly prefer Indesign or Xpress and with good reason, I think. –  Charles Stewart Dec 9 '10 at 7:22
@Charles Stewart Thanks - I've updated the answer to reflect that. –  Michael Ekstrand Dec 9 '10 at 19:32

TeX is a typesetting language. You can use it to create high-quality PDF output. It's used a lot in the sciences because it handles equations very nicely. TeX is the base language; LaTeX is an extension of TeX that makes some common tasks easier. I’m sure someone else can explain some of the nuances better than I, as I’m still kind of green myself.

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In addition to mathematic typesetting, LaTeX also performs heroic feats of cross-referencing without breaking a sweat. I think this feature endears it to academics in general. –  Sharpie Dec 9 '10 at 4:20

If you would rather use anything but Word, then TeX is for you.

"What is it used for?" - Typesetting every imaginable sort of document in commercial quality.

"Who uses it?" - Scientists, teachers, professors, musicians, illustrators, the Word-averse, technical writers, book publishers and more. I haven't used Word for any document (except when I've absolutely had to) since I started using TeX.

"What is it an alternative to?" - Word-processing programs, graphing utilities, graphics programs, etc

"How widespread is its use?" - To be honest, not that well-known beyond academia.

"Plain text or WYSIWYG?" - Generally, plain text mark-up. That's why we love TeX so much. That said, there are programs, such as LyX, that offer WYSIWYG with the power of TeX, so you could definitely check that out.

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@Jimi: I have a feeling that the plain text mark-up bit would be why I would love it as well. Is there any relation to troff/groff? I don't know much about them other than you can provide macros in plain text that troff interprets in specific ways. –  Robert S Ciaccio Dec 9 '10 at 6:58
+1 for "If you would rather use anything but Word, then TeX is for you." –  Matthew Leingang Dec 9 '10 at 13:50
A bit of a pet peeve: Lyx doesn't offer WYSIWYG, it offers WYSIWY Mean. lyx.org –  Willie Wong Dec 9 '10 at 19:01
@calavera: I just looked up g/troff and it looks interesting. While it's also a typesetting program, it may have some fundamental differences from TeX/LaTeX that, perhaps, others more knowledgeable than I am could expound upon. I'm not sure how widely used g/troff is but so many macros and packages have been written to harness TeX since Knuth created it that I would think it is way more versatile than g/troff. –  Jimi Oke Dec 10 '10 at 0:34
@Matthew: Thanks! And @Sharpie, I certainly do not dispute the versatility of Word but I simply prefer to use LaTeX for all my documentary output, from the mundane to the monumental. I love text-based environments (Emacs, TextMate, etc) and the fact that you can edit a LaTeX document from any machine. –  Jimi Oke Dec 10 '10 at 0:41

Personally, I don't like LaTeX because it's just too much hard work for the easy stuff. Oh, and I hate the standard appearance (which is probably customizable, but no academics ever do).

But, and I quote:

"Is it a worthwhile technology to invest time in learning as a programmer/technology junkie who hates word processing apps with a passion? I'd rather write a wiki page than a letter in Word. But I don't know if that means I should switch from plain text to TeX or if that's like using a bazooka when all I need is a hammer."

You are exactly the right type of person to learn LaTeX. You like programming. You hate Word. You're willing to geek it up. You don't have a particular need to be productive with this tool any time soon.

Go for it, and godspeed.

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I guess I'm not an academic after all. :( –  frabjous Dec 9 '10 at 20:28
'geek it up'... lol. your answer cracked me up :) –  Robert S Ciaccio Dec 10 '10 at 1:31
I'm grateful even when my professors get the spelling right. To have them customize the layout would be a marvel. I have seen their LaTeX sources and they use it as a 'Word with maths'. \bf and \mbox and \vspace and \noindent everywhere! –  marczellm Jan 23 '13 at 10:03
+1 and you don't have a particular need to be productive with this tool any time soon... –  nutty about natty Mar 28 '13 at 17:41

LaTeX is a computer program for producing professional-quality articles, books, and other documents using a special markup language where the user describes the contents of the document, rather than specifying formatting directly. For example, to define a section heading, one would write \section{Section Heading}, rather than specifying "18-point bold Arial". This means that all features of a document can be rendered in a consistent manner, without having to worry about using the correct fonts and formatting.

LaTeX provides an advanced typesetting engine designed to ensure the best possible flow of text, unlike word processing software such as Word which does not attempt to optimize text flow. This means that output generated by LaTeX has a distinctive, "beautiful" look and feel more akin to classic books than a typical computer document. In addition, LaTeX is designed for high-quality typesetting of mathematical expressions, making it well suited for mathematical and technical documents.

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