I’ve recently talked about how XSLT is pretty good as a presentation layer for web applications. XSLT is a powerful template language by itself but it is woefully missing several functions and interfaces which you will eventually find absolutely necessary for some purposes. EXSLT is the solution. EXSLT is a collection of extensions for the XSLT. It has numerous functions and features that XSLT is missing.
EXSLT functions are widely used and extensively tested. Not only is it available for every server-side XSLT engine, but it is also available in Mozilla Firefox, Safari, Chrome and Opera.
Unfortunately, as usual Internet Explorer throws a wrench in the whole works. Microsoft in their infinite wisdom decided not to implement the EXSLT functions and specs in their browser. Instead they implemented their own MSXSL extensions, which are frankly terrible. It doesn’t have anywhere near as much functionality as EXSLT and will never work with anything other than Internet Explorer.
The most common (and difficult to replicate) EXSLT function that I use is set:distinct. It is an extremely powerful function that lets you grab a distinct list of nodes, attributes, or values without impacting your current context in the style sheet.
This function is not available in any form in MSXML, so I decided to build it.
