World Public Library: http://www.worldpubliclibrary.org/
WorldTel: http://www.world-tel.com/
WWW Virtual Library (VL): http://vlib.org/
Xerox: http://www.xerox.com/
Xerox Research Centre Europe: http://www.xrce.xerox.com/
Xlibris: http://www2.xlibris.com/
XML (extensible markup language): http://www.w3.org/XML/
Yahoo!: http://www.yahoo.com/
Yahoo! Books: http://shopping.yahoo.com/books/
Yahoo! France: http://fr.yahoo.com/