Welcome to XML Calabash
XML Calabash is an implementation of XProc: An XML Pipeline Language.
See the XML Calabash project status page for more details.
You can download Calabash and/or read the (very little bit of) documentation. Calabash also ships with the <oXygen/> xml editor (as does Saxon-EE which includes support for validation with W3C XML Schema).
There is a reference guide to XML Calabash.
If you're interested in tracking the development of XML Calabash, you might be interested in:
Following the code development at github.
Following (or +1ing or circling or whatever one does with Google+ pages) the Google+ page for XML Calabash.