Background

With TEX, Knuth designed a formatting system that is able to produce a large range of documents typeset to extremely high quality standards. For various reasons (e.g. quality, portability, stability and availability) TEX spread very rapidly and can nowadays be best described as a world-wide de facto standard for high quality typesetting. Its use is particularly common in specialized areas, such as technical documents of various kinds, and for multi-lingual requirements. The TEX system is fully programmable. This allows the development of high-level user interfaces whose input is processed by TEX's interpreter to produce low-level typesetting instructions; these are input to TEX's typesetting engine which outputs the format of each page in a device-independent page-description language. The L^ATEX system is such an interface; it was designed to support the needs of long documents such as textbooks and manuals. It separates content and form as much as possible by providing the user with a generic (i.e.  logical rather than visual) mark-up interface; this is combined with style sheets which specify the formatting. Recent years have shown that the concepts and approach of L^ATEX are now widely accepted. Indeed, L^ATEX has become the standard method of communicating and publishing documents in many academic disciplines. This has led to many publishers accepting L^ATEX source for articles and books; and the American Mathematical Society now provides a L^ATEX package making the features of $\mathcal A$ $\!\mathcal M\!$ $\mathcal S$-TEX available to all users of L^ATEX. Its use has also spread into many other commercial and industrial environments, where the technical qualities of TEX together with the concepts of L^ATEX are considered a powerful combination of great importance to such areas as corporate documentation and publishing. This has also extended to on-line publishing using, for example, PDF output incorporating hypertext and other active areas. With the spreading use of SGML-compliant systems (e.g. Web-based publishing using HTML or XML) TEX again is a common choice as the formatting engine for high quality typeset output: a widely used such system is The Publisher from ArborText, whilst a more recent development is the object-oriented document editor Grif. The latter is used for document processing in a wide range of industrial applications; it has also been adopted by the Euromath consortium as the basis of their mathematician's workbench, one of the most advanced of the emerging project-oriented user environments. Typeset output from SGML-coded documents in these systems is obtained by translation into L^ATEX, which will therefore soon also be a natural choice for the output of DSSSL-compliant systems.

Because a typical SGML Document Type Definition (DTD) uses concepts similar to those of L^ATEX, the formatting is often implemented by simply mapping document elements to L^ATEX constructs rather than directly to `raw TEX'. This enables the sophisticated analytical techniques built into the L^ATEX software to be exploited; and it avoids the need to program in TEX.