Google's recent release of AJAXSLT is a good first step towards unifying XSLT services in the browser. Currently, IE uses a rental-model XSLT processor, which is inconvenient for stateful Javascript applications like direc.tor because you have to instantiate a new object every time you make any change to the XSL stylesheet. Hopefully the browser vendors will converge towards a common interface, like they did with XmlHTTP, in the future.

Even though the AJAXSLT library supports Safari and Opera, it's still not ready for prime time, mostly because of performance reasons. In IE and Firefox, the AJAXSLT library is really just a pass-though for the compiled XSL services. However, in Safari and Opera the XSL transformations are done in interpreted Javascript, making it much slower than IE and Firefox. Many people have asked me if I could use this library to make direc.tor work with Safari. The answer is yes, but for anyone with more than a couple hundred bookmarks, the poor performance would become unbearable very quickly.