My Slides I write raw XML according to a Slides DTD in XEmacs . Resulting HTML slides are styled with a CSS stylesheet and displayed in any web browser. I get to use XEmacs. Not dependant on any one supplier's product. Pages display on any web browser.
Tools are free and portable.
XSLT technology is new. Tools aren't well packaged. Writing XML code isn't for everyone. The XML document is processed with the Xalan XSLT processor which uses the Xerces XML parser. Search engines have to make guesses about page categories by looking at the contents.