See also:
Higher Intellect Presents the server that hosts open source and abandonware software as well as other files that seem important to its users. Also offers a tracker to find other Hotline servers. http://www.preterhuman.net/
Hotline Protocol Official listing for versions of the Hotline protocol released under the GNU Public License by Hotsprings, Inc. through the OpenSprings project. http://sourceforge.net/project/showfiles.php?group_id=77706&package_id=78748
Major Mac Backup Offers archiving and backup services on Hotline, Carracho, and KDX servers, with a particular focus on Macintosh users. http://mmb.kicks-ass.net/
Naibat.com: Hotline File Sharing Hosts a tracker, several user guides in PDF format, old client and server software for historical purposes and a collection of useful links. http://www.nailbat.com/content/view/14/32/
VivaHX News, features, guides and reviews related to Hotline. http://www.vivahx.com/
Wikipedia.org: Hotline Communications Presents the now defunct company that created the Hotline Connect protocol, their software suit, its history, and its successors. http://en.wikipedia.org/wiki/Hotline_Communications
Hotline's Civil War Salon.com 21st feature that outlines the legal battles that have ensued between Hotline Communications and the inventor of the Hotline protocol, Adam Hinkley. (February 25, 1999) http://archive.salon.com/21st/feature/1999/02/25feature.html
Hotline to the Underground Salon.com 21st feature that explores the culture of the Hotline community. (February 24, 1999) http://archive.salon.com/21st/feature/1999/02/24feature.html