The package provides a LaTeX interface to pdfTeX's micro-typographic
extensions: character protrusion and font expansion.  The package allows
you to restrict character protrusion and/or font expansion to a certain
set of fonts, or to certain parts of the document (for example, based on
selected language), and to configure micro-typographic aspects of the
fonts in a straight-forward and flexible way.  Settings for various fonts
are provided.  The bundle also provides a letterspace package; this
improves on the alternatives (letterspacing and soul), and also provides
a means of protecting ligatures--notably those in fraktur fonts.