The package is used in documentation files (that use the package); with it the code listings will highlight (for example) pairs of curly braces with matching colors.

Other delimiters like \if ... \fi, are highlighted, as are the names of new commands.

All this makes code a little more readable, and helps during process of writing.

Three options are provided, including a non-color option designed for printing (which numbers delimiters and underlines new commands).

The author is Federico Garcia. The package is Copyright © 2010 Federico Garcia.