Mozilla Firefox (formally abbreviated as Fx or fx, informally abbreviated as MF), is a free and open source web browser, using Gecko typesetting engine, supports multiple operating systems, such as Windows, Mac OS X and GNU/Linux Wait. The browser provides two versions, the regular version and the ESR (Extended Support Release) version. The ESR version is specially created by Mozilla for those companies that cannot or do not want to upgrade every few weeks. The upgrade cycle for Firefox ESR version is 12 months, while the upgrade cycle for ordinary Firefox is 4 weeks. Since the source code of the browser is open, there are some third-party compiled versions for use, such as pcxFirefox, Cangyue Browser, tete009, etc. Learn the basic functions of the Firefox browser-bookmarks, tabs, search, add-ons, page operations, etc.