The package provides macros for manipulating strings — testing a string’s contents, extracting substrings, substitution of substrings and providing numbers such as string length, position of, or number of recurrences of, a substring.

The package works equally in Plain TeX and LaTeX (though e-TeX is always required). The strings to be processed may contain (expandable) macros.

The author is Christian Tellechea. The package is Copyright © 2008-2013 Christian Tellechea.