We have seen from our discussions last week that standardisation brings about great advantages in terms of cross-browser compatibility however browser developers maintain differences in those standards for competitive and other reasons. The XHTML Document Object Model (XHTML DOM) is no different this respect and the W3C (2005) define it as “a platform- and language-neutral interface” whilst Mozilla (2009) state that “many browsers offer extensions beyond the W3C standard” going on to qualify that care must therefore be taken in their use in order to achieve cross browser compatibility.
It is understandable why browser offers extensions over and above the W3C recommendation to make their browser more attractive to developers who want to provide the latest cutting edge usability features and styling. However this often comes at the expense of some of their users who cannot take advantage of such techniques that their browsers do not support, unless of course the developer can require or redirect to a browser that supports their chosen DOM (extremely subjective unless in a controlled environment). This differing browser implantation has lead to different levels of DOM being adopted in different browsers. Given that browsers and evolving to build upon and extend basic DOM levels and sites are being developed to take advantage of new techniques in usability and accessibility, we are left with a minefield of stability for the user.
In reality we do not receive outcries from users that a particular popular site (e.g. Facebook, eBay) does not work properly in a current version of a major browser as the major sites are tested properly for compatibility. I am sure, however, that many untested sites would receive more traffic should they test for compatibility properly. As a result it seems extremely unwise to maintain more than a single agreed XHTML DOM standard and I would always recommend the use of the one that it the most impartial, open source and with no commercial agenda: W3C.
Mozilla Developer Centre (2009) What is the DOM? [Online]. Available at https://developer.mozilla.org/en/Gecko_DOM_Reference/Introduction#What_is_the_DOM.3F (Accessed 26 September 2010).
W3C (2005) Document Object Model (DOM) [Online]. Available at http://www.w3.org/DOM/ (Accessed 26 September 2010).