Implementations in Web browsers - WHATWG WikiHTML5 General canvas with some limitation implemented in Firefox, Opera, Safari, and Konqueror 4, with ExplorerCanvas emulated in Internet Explorer getElementsByClassName implemented in Firefox 3, Safari 3.1, Opera 9.5 localStorage and sessionStorage implemented in Firefox 2, IE 8, Safari 4 Database storageimplemented in Safari 3.1 and iPhone Safari 2.0 Custom content handlers partially implemente
