# TeX system and digital typography

## 1. Introduction

With development of computer science in last century there emerged new branches when computers started to help. One of them was digital typography. Although it was influenced (and also delayed) by development of printers (in particular dotmatrix and laserprinters) a lot, computers contributed to formation of digital typography noticeably. Donald Knuth, Professor Emeritus of The Art of Computer Programming at Stanford University noticed that computers could do majority of work in typography process – lenghty preparation of printing matter and type casting of lead could be replaced by work of computers. It was the first and the most important step for digital typography.

There are lot of advantages of this approach. You don´t need any typesetter, you can do the whole design of page or book by yourself. You can correct any mistake in text quite easily, simply by rewriting appropriate passage or sentence. You don´t need remake whole page like before. When the document is prepared, you can also simply change e.g. font of whole text, or change a style of certain paragraph, size of title font etc. Finally you can print the document on any available printer. And this all thanks to TeX systém, which is free, because Knuth gave the whole program free of charge for public purposes.

Despite a lot of advantages, there are some disadvantages too. Output from TeX is file which can´t be edited. When you use e.g. .doc format from MS Word, you can easily change its contents, but with TeX you lose this ability. Also, TeX file is a bit larger, but nowadays it isn´t such a big problem.

## 2. TeX and his father

Donald Erwin Knuth, author of TeX is worldwide respected programmer and mathematician. He strongly influenced both analysis of algorithms and mathematics. His the most famous work is set of books named The Art of Computer Programming with parts: Fundamental algorithms, Seminumeral algorithms and Sorting and Searching algorithms. These books are so far the hugest publications on problem of programming. He still works on further volumes. Also noticeable are works: Computer and Typesetting, Literate programming, Discrete mathematics, TeXBook and MetafontBook. The two last of them deal with topic of digital typography and Knuth describes the whole process of creating and programming of this systems. Thanks to these significant books he is the most appreciated computer book author nowadays. In 1996 he even visited our faculty gave a lecture and was awarded doctorate honoris causa.

## 3. TeX as a program

Knuth was the first to notice that computers could help us with typography. In late 70´s he was disgusted by ugly font used in mathematical and scientific publications published in America which become almost unreadable, so he started working on the TeX to improve appearance of technical literature. While working he had to solve several problems connected with it. E.g. He searched for the best equations describing curves between several points. Because digital typography means that fonts and text are represented in computer by dots of matrix thus in digital form, he solved problem how to convert nice curves creating fonts and characters, which were typecasted from lead before, into dots. He gradually created new font called Computer Modern character by character which has been used in digital typesetting so far. He also wanted to solve, how to break lines and pages properly. When line is broken, some long and unwanted gaps between words can occur and to avoid this phenomenon you must calculate the best place on line when the line could be broken. The same rule applies for pagebreaking. So he came up with very sophisticated algorithms which solved these problems. This all he describes in TeXBook and Digital Typography. It is quite interesting that the most dificult character to design was S, question mark and the infinity sign. All characters of alphabet are described by mathematical formulas and equations in TeX. Its also very interesting, that Knuth himself stated that anybody who reveal any mistake or error in TeX will be given a bonus. The first version of program was released in 1982 and the newest version of TeX has number 3.14159 which represent the beginning of pí number.

Although TeX is spelled t e x, we pronounce it [tech] because individual characters are of Greek origin. Knuth want to express that TeX should serve for technical literature purposes.

A work with TeX system we can compare to programming in some other programming language. First of all we make source code (in any ASCII text editor or notepad), compile it with TeX, it possibly can report errors, but after correcting them, you obtain translated document in DVI (device independent) file. Device independent because no matter which computer you use for viewing DVI file, you will see the same result. Tex itself contains about 300 basic marking commands called primitives. With help of macrolanguage, which is encapsulated in TeX, you can create new commands with more complicated construction from basic commands. Thanks to it you can create interface which meets your needs and which is suitable for you. LaTeX and AMSTeX for typesetting of mathematical formulas are the most popular ones. And are widely used by mathematician. DVI file is device independent but for comfort viewing its quite convenient to convert it into another format e.g. PDF (printing document file) or PS (postscript). Because PDF and PS browsers are widespread.

## 4. TeX as utility

When writting thesis or technical document you appreciate all features of TeX. No other program is so easy to use than TeX. You can typeset very complicated mathematical formulas, draw graphs and insert them into a text, design new typefonts, prepare books for printing and so on very easily. For this reasons TeX is used worldwide by academics and students. It looks more sophisticated than document created in MS Word or Powerpoint. There are about milion of TeX users in the world. Even in Czech Republic there are CSTUG which means czech and slovak tex user group.

## 5. TeX and its future

TeX typeset documents are very suitable to became world standard of exchange of academic information throught internet, but another markable language is expected to replace it – XML. Extensible markable language. XML puts emphasis on contents of document not on appearance. So nowadays there is a tendency to share documents in XML format, but use TeX for documents and its contents to be prepared for printing.

last modified: 2023-01-21

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