From the post:
Testbed for trying out XSLT 3.0 (http://www.w3.org/TR/xslt-30/) techniques.
Since few people yet have much (or any) experience using XSLT 3.0 on more than toy examples, this is a public, medium-sized XSLT 3.0 project where people could try out new XSLT 3.0 features on the transformations to (X)HTML(5) and XSL-FO that are what we do most often and, along the way, maybe come up with new design patterns for doing transformations using the higher-order functions, partial function application, and other goodies that XSLT 3.0 gives us.
If you haven’t been investigating XSLT 3.0 (and related specifications) you need to take corrective action.
As an incentive, read Pearls Of XSLT And XPath 3.0 Design.
If you thought XSLT was useful for data operations, you will be amazed by XSLT 3.0!