If you are an end user and experiencing a problem, please contact your company IT help desk. If you are an IBM Traveler administrator experiencing a problem, please open a PMR with your IBM. Mozilla Firefox ( or simply Firefox) is a free and open- source web browser developed by The Mozilla Foundation and its subsidiary, Mozilla Corporation. Firefox is available for Windows, macOS, Linux, BSD, illumos and Solaris operating s sibling, Firefox for Android, is also available. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web.