Lambda the Ultimate

It rapidly became clear that a single language runtime is too limited for general applications ... as a minimum we needed both a linear-flow language and a recursive tree composition language ... while declarative languages are excellent for rapid assembly of XML operations, they are terrible for expressing business logic and logical flow-control ... Our other declarative language is XML Recursion Language (XRL). XRL is like XInclude with services, in which inclusion references fire service invocations into the URI address space in order to recursively compose an XML document. XRL is an elegant and powerful way of building XHTML applications ... The active URI, in combination with the local NetKernel environment, is a functional program - Introducing NetKernel.

Main site; Tour.

It's another XML pipeline (there's a Freshmeat project that lets Coccoon apps run in NetKernel), apparently from HP, which might interest people here.