Net-Hotline - A set of modules for utilizing the Hotline protocol in a Perl environment. - http://search.cpan.org/dist/Net-Hotline/
Free HL Iconlib - A free and opensource Java library for extracting icons and GIF-images from the hotline.dat file of the Hotline software provided by Hotsprings, Inc. - http://www.markusstengel.de/hliclib.html