The package finds strings (e.g. (parts of) words or phrases) and manipulates
them (apply any macro), thus turning each word or phrase into a possible
command. It is written in plain XeTeX and should thus work with any format (it
is known to work with LaTeX and ConTeXt). The main application for the moment
is XeIndex, an automatic index for XeLaTeX, but examples are given of simple
use to check spelling, count words, and highlight syntax of programming
languages.