ModEnc is currently in Maintenance Mode: Changes could occur at any given moment, without advance warning.
ModEnc:Firefox
Under all circumstances and without exception, the latest currently available, officially stable version of Mozilla Firefox is the browser in which all code has to work and in which all layout has to look good in.
Cross-browser compatibility is encouraged, but under no circumstances (except for Administrative Decree) shall a standards-compliant feature be removed because it is not supported by other browsers. Conversely, no feature shall be included that breaks design, code or functionality under Firefox, no matter if it works fine in other browsers.
No user is forced to use or test in Firefox. But be aware that no compatibility is guaranteed for other browsers.