History of Firefox updates automatically update Firefox to the latest version without notifying the user, a feature that the web browsers Google Chrome and Internet Explorer 8 and above have already implemented, although the user is able to disable that function. Mozilla improved regular startup time for Windows users. Firefox 16 was released on October 9, 2012. Plans for this version called for fixing of bugs still outstanding involving support of new features in Mac OS X Lion, improvements to startup speed when a user wants to restore a previous session, and support for viewing PDF files inline without a plugin. Opus audio
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