Open source Eclipse XML Editong plug-in

Is anybody working on or aware of an open source Eclipse plug-in for 
editing XML and doing XMLish things (XSLT, XPath, schema, DTDs, etc.)? 
My initial googling hasn't turned up anything promising. I've found a 
couple of commercial and closed-source/free-beer options. I've also seen 
a couple of more-or-less abandoned projects that never achieved liftoff, 
but so far nothing in active development.

-- 
Elliotte Rusty Harold  
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim