Features of Firefox Features of Firefox Here are some of the features that distinguish Mozilla Firefox from other web browsers, such as Internet Explorer. To avoid interface bloat and ship a relatively smaller core customizable to meet individual users' needs, and allow for corporate or institutional extensions to meet their varying policies, Firefox relies on a robust extension system to allow users to modify the browser according to their requirements instead of providing all features in the standard distribution. While Opera and Google Chrome do the same, extensions for these are fewer in number as of late 2013. Internet Explorer also has an
Quirks mode Web Consortium, which maintains the XHTML specification, suggests that authors of XHTML documents could consider omitting the XML declaration. Henri Sivonen compiled a list of various document types and how they are treated in the most common browsers, showing whether pages are rendered in Quirks, Standards, or Almost standards mode. The criterion used for "Almost standards mode" is non-standard table cell height rendering. This table applies to content served with the Content-Type text/html. Content served with the Content-Type application/xhtml+xml is rendered in Standards mode in Chrome, Firefox, Internet Explorer 9, Safari, and Opera. Internet Explorer 6, 7, and 8 do