Writing classes and packages for L^ATEX2_e

L^ATEX is a document preparation system that enables the document writer to concentrate on the contents of their text, without bothering too much about the formatting of it. For example, chapters are indicated by \chapter{<title>} rather than by selecting 18pt bold. The file that contains the information about how to turn logical structure (like `\chapter') into formatting (like `18pt bold ragged right') is a document class. In addition, some features (such as colour or included graphics) are independent of the document class and these are contained in packages. One of the largest differences between L^ATEX 2.09 and L^ATEX2_e is in the commands used to write packages and classes. In L^ATEX 2.09, there was very little support for writing .sty files, and so writers had to resort to using low-level commands. L^ATEX2_e provides high-level commands for structuring packages. It is also much easier to build classes and packages on top of each other, for example writing a local technical report class cetechr (for the Chemical Engineering department) based on article.