Bare-bones Pie API implementation

Looks like Mark Pilgrim had a productive weekend (Atom API Implementation) and now has working (RESTish, apparently) stripped-down but functional implementation of the the Pie (Mark is still calling it Atom – I will call it Pie until a consensus emerges on a new name) API (application programming interface).
I gather this is a proof of concept intended to challenge some assertions about Pie and the REST architectural model:

This implementation is entirely self-contained within a single CGI script and runs on a default Apache install with no .htaccess tricks. Hopefully this will clear up a number of misconceptions about REST APIs in general and the Atom API in particular, especially the one about it being impossible to implement as a single CGI script on a default Apache install with no .htaccess tricks. It is possible; I’m doing it.

Mark’s also got a sandbox blog set up to test his API implementation.

NOTE: I’m posting this in my Syndication category, but maybe I need an API category, maybe one called Interfaces? Or maybe I should rename Syndication “Formats” to reflect the fact that RSS and potentially Pie etc. represent more than simply a way of generating syndication feeds.