" is a simple markup language used to define Web page components for dynamic assembly and delivery of Web applications at the edge of the Internet."
This spec was introduced in May but I didn’t hear about it at the time. Its backers – Akamai, ATG, BEA Systems, Circadence, Digital Island, IBM, Interwoven, Oracle, and Vignette – want to split pages into little bits that can be cached nearer to users, so that web servers don’t need to send whole pages so often. Sjoerd Visscher thinks XML-RPC in the browser is a better way to go.
03/25/02 update: Web Hosting Strategies.
08/15/04 update: their last news is dated 10/30/02 so this one seems toasted.