More on TEX and Aleph

Aleph is a typesetting system combining features of Omega and e-TeX. Both are in turn extensions to the TEX typesetting system developed by D. E. Knuth.

Although very often compared with XML and associated lenguages, they are in fact quite different things. The main concern of XML is structured data, while TEX is a typesetting system, perhaps rendering XML document previously transformed with XSLT. With TEX and derivatives you can even carry out a further kind of transformation - while XSLT transforms documents based on their content, TeX can accomplish transformations based on their format selecting one of the possible renderings.

For example, we can require tables to measure exactly the text width, but if they are too narrow or too wide, they will have another size (for example, a half the text width, and the text width plus 2 cm or even rotated in a landscape page). Only by actually typesetting several times these tables and see what happens we can choose the right solution. This kind of tranformations is independent of data transformation and it's essential in many applications.

For more on that, see the talk (in Spanish) I gave in the IV Jornadas de Bibliotecas Digitales (JBIDI 2003, Alicante, Spain). Paper (PDF, 82k). Slides (PDF, 106k).