Hotline clients allow a connection between user and server. They essentially provide the user with an experience, allowing them to view files and folders on the server, read the news BBS, chat and communicate with the community.
Because hotline was originally intended as a chatting p2p client, most people focused on one or the other. Hotline is a good place to find files, however it also houses a fairly large chat community, and allows you to communicate with other users. Since hotline came prior to Facebook, torrents, and the Gnutella network, it truely was remarkable for its time. It still exists, and you can feel free to download one of the clients below and see for yourself.
Stop over to the server: obsession.ath.cx and say hi.
Downloads
Official Clients
Openline is the source code released under the GNU General Public License.
Clones
PhareRouge / Gloarbline (Java, multiple platforms)
Under development
Many hotline users have decided over time to develop their own clones, serving particular purposes that are not available in other clients or featuring a personalized user interface. These are the clients that are being actively developed as of April 2010 by the Hotline community:
Nostalgia
XCC pr2.4, written in REALbasic. XCC is (for now) a Mac client aimed at end users and server admins.
Obsession, written in Qt 4, although currently focused mainly on Windows users.
Nostalgia, written in Obj-C using Cocoa from the ground up. For 10.5 +.
XCC version 2.4
Obsession Hotline client