CL-libxml2 is a Scripts software developed by archimag. After our trial and test, the software is proved to be official, secure and free. Here is the official description for CL-libxml2:

EditByMarydown: Interfaces for tree manipulation (like cxml-stp)
Interface for an HTML 4.0 non-verifying parser
Specific APIs to process HTML tree, especially serialization
XPath API
XSLT API
Custom URL resolvers
XPath extension functions
XSLT extension elements
Translate Libxml2 and libxslt errors to Lisp conditions
iterate drivers for enumerate child nodes and etc.
Simple and Compact syntax for generating XML (xfactory)