Use of preprocessors

• Simple if-else tests a la the C/C++ preprocessor
• FORMAT variable can be used to test on format, e.g.,
• if latex/pdflatex do one sort of code (raw LaTeX)
• if html, do another type of code (raw HTML)
• Easy to comment out large portions of text
• Easy to make different versions of the document
• The mako preprocessor is really powerful - gives a complete programming language inside the document!