I've started work on producing a PHP port of Dave's OPML renderer. 
I've got the basic structure going - but I've still got a long way to go. 
Take a gander. I've got lots to build - a component to show RSS and Atom, a method by which I can do inclusion and a breadcrumb method. The RSS component will probably be a link to the website and a link to the XML - and a link to a rendering of that XML. 
The interface of the link above is frankly horrible. The end result will be configurable and it will be possible to style it in a number of ways (so, for instance, it will be possible to have stylesheets for mobile and for standard rendering). 
The inclusion is the bit I'm having to wrap my brains around. The problem is that there are two ways that I can think of doing it - one way is efficient but very messy to code, and the other is very processor-hungry. 
I'm going to be starting a mailing list later in order to piece together the components to eventually supplement the OPML Editor's server functions but on the LAMP stack. 
If you've got any experience programming in PHP5, especially if you know how to use the XML tools (I'm using, on the advice of Kosso, the SimpleXML libraries rather than the DOM - and the SimpleXML implementation of XPath), then please drop me a line and get involved. I'll be releasing source code later - let's really rev the motor up and get this thing working! 
Generally, you can tell what kind of day I'm having based on what I'm writing about. If I'm talking about politics and religion, I'm having a bad day. If I'm talking about them in the abstract, I'm having a slightly better day. If I'm talking about technology in the abstract, I'm having a good but unproductive day. If I'm talking about technology in the specific "I'm building something, go check it out" way, I'm having a good and productive day.
