Dentro de la web de Google Code, se puede ver un proyecto recente AJAXSLT:

AJAXSLT is an implementation of XSL-T in JavaScript, intended for use in fat web pages, which are nowadays referred to as AJAX applications. Because XSL-T uses XPath, it is also an implementation of XPath that can be used independently of XSL-T.

Via SP veo que ya tienen una página en SourceForge