» DefBot    A very customizable automated Hotline client for server administration and user moderation.    http://www.s-and-m-software.com/

» Fidelio    Open source GNU/Linux client that supports most of the latest Hotline features.    http://fidelio.sourceforge.net/

» Frogblast    A freeware clone of the Hotline client software written exclusively for Macintosh OS X, using Apple's Cocoa APIs.    http://ayanamichan.com/richard/frogblast/

» GtkHX    A Hotline client written for Unix/Linux-like operating systems. It employs the Gtk+ environment for the front-end and utilizes a back-end based on the HX project.    http://gtkhx.sourceforge.net

» HotPants    Open source Hotline 1.2.3-compatible client for Macintosh OS X.    http://homepage.mac.com/haveblue/hotpants/

» Hotline Client How-To Guide    Offers an explanation of the way the official client works, also includes a FAQ on connection errors and navigation tips. Apparently no longer maintained but still of interest.    http://www.hl123.com/hotline/

» Hotline-Tools    Shareware Macintosh client and utilities for Hotline users.    http://www.hotline-tools.com/

» JHL    A Java-based Hotline client.    http://jhl.johnl.org

» Monica    A shareware Macintosh download utility for the automated downloading of files from the Internet using popular file transfer protocols, including the Hotline protocol.    http://www.blackdiamond.co.za/bdmonica.html

» SilverWing    A Hotline client for BeOS. A version is available for the x86 hardware platform as well as PPC.    http://hp.vector.co.jp/authors/VA013465/silverwing-beos/

» Underline    A variant of the OpenLine client for MacOS and Windows that supports blowfish encryption. Licensed under GNU GPL.    http://www.hyperspasm.com/underline/