It was originally written by Shawn Betts, the primary author of keyboard-driven ratpoison and Stumpwm tiling window managers. Formerly an extension for the Mozilla Firefox browser, it is now developed for XULRunner as a stand-alone application. Since Firefox 52 ESR (September 2018), when the last official Mozilla browser that supported XULRunner reached end-of-life, there is no officially-supported browser from Mozilla for Conkeror to be based on. Firefox forks like Pale Moon and Waterfox continue to bundle XULRunner and can be used to run Conkeror.