Dialcat was a remote character-based interface used to access Dynix-based library catalogs. By using a modem and a terminal emulator, personal computer users could use a functionally identical version of the menu-driven catalog interface available on the dumb terminals that could be found in Dynix-using libraries. As Internet access became more widespread in the mid-1990s, Dynix-using libraries made Dialcat available via .
Using Dialcat, a library patron could, among other things, browse and search a library system's collection by subject, author, keyword, and title; place holds on desired items, to be retrieved at the library branch of their choice; view announcements and events relevant to the local library system; and browse the world wide web with an instance of Lynx running on the remote catalog server.
As web browsers became a ubiquitous component of personal computing, Dialcat was first supplemented with, and eventually replaced by, web-based catalog interfaces, which integrated rich catalog data (such as book cover images) and could be accessed from public web terminals and kiosks, most of which do not allow telnet use. Dialcat's advantages over web-based front-ends were performance over low-speed (i.e. dial-up) internet connections, availability to modem users without an internet service provider, greater perceived ease-of-use among older library patrons unskilled in the use of computer mice, and sheer blistering speed of use (avid library patrons who had habitually used Dialcat for more than a year could often log on, locate and place a hold on a given book, and log off within 30 seconds, sometimes without even looking at the screen). Nevertheless, Dialcat's modest strong points were eventually outweighed by the need to conserve administration resources by focusing on a single catalog interface: Dynix ended its official support for Dialcat, and Western Washington's Timberland Regional Library system, one of the last known Dialcat-using holdouts, stopped using the program in early 2005.