Running Linux, 5th Edition - Matthias Kalle Dalheimer [16]
There is a role for other ways to create documents, though. The system configuration files you need to edit on Linux from time to time, as well as programming for application development, require the use of simple text processing. The most popular tools for creating such documents are vi and Emacs, described in detail in Chapter 19.
Text processing can also be used with separate formatting tools to create very readable and attractive documents. With a text processing system, the author enters text using a "typesetting language" that describes how the text should be formatted. Once the source text (in the typesetting language) is complete, a user formats the text with a separate program, which converts the source to a format suitable for printing. This is somewhat analogous to programming in a language such as C, and "compiling" the document into a printable form.
The most famous text formatting language is HTML, the markup language used by virtually every page on the World Wide Web. Another popular text processing language is DocBook XML, a kind of industry-standard set of tags for marking up technical documentation, which is also used by the Linux Documentation Project (to be discussed later in this chapter).
We'll look at several text formatting systems in Chapter 20, Text Processing: TEX (developed by Donald Knuth of computer science fame) and its dialect LATEX, groff, the GNU version of the classic troff text formatter originally developed by Bell Labs); Texinfo (an extension to TEX used for software documentation by the Free Software Foundation); and Docbook.
Commercial Applications
In addition to the more than fifteen hundred Linux applications maintained by Linux distributors such as Debian, a groundswell of support exists from commercial application developers for Linux. These products include office productivity suites, word processors, scientific applications, network administration utilities, ERP packages such as Oracle Financials and SAP, and large-scale database engines. Linux has become a major force in the commercial software market, so you may be surprised to find how many popular commercial applications are available for Linux. We can't possibly discuss all of them here, so we'll only touch on the most popular applications and briefly mention some of the others.
Oracle, IBM, Informix, Sybase, and Interbase have released commercial database engines for Linux. Many of the Linux database products have demonstrated better performance than their counterparts running on Windows servers.
One very popular database for Linux is MySQL , a free and easy-to-use database engine. Because MySQL is easy to install, configure, and use, it has rapidly become the database engine of choice for many applications that can forego the complexity of the various proprietary engines. Furthermore, even though it's free software, MySQL is supported professionally by the company that developed it, MySQL AB. We describe the basic use of MySQL in Chapter 25.
MySQL does not include some of the more advanced features of the proprietary databases, however. Some database users prefer the open source database PostgresSQL, and Red Hat features it in some of its products. On the other hand, MySQL is catching up really quickly; the next version will contain support for distributed databases, for example.
A wide range of enterprise applications is available for Linux in addition to databases. Linux is one of the most popular platforms for Internet service hosting, so it is appropriate that high-end platforms for