Saxon9 is the new XSLT2 processor exchanging Apache Xalan to process ODF for the XML based filters.

I can be optained from https://saxon.svn.sourceforge.net/svnroot/saxon/latest9.0/build/source-9.0.0.7-bj.zip 
were the used source bundle was provided for OOo from the maintainer (Michael Kay).

The home of Saxon-B is the http://saxon.sourceforge.net/ page. 

The license for Saxon-B is explained from:
http://www.saxonica.com/licence.html