Complex sentence: XSLT is often used to convert XML data into HTML or XHTML documents for display as a web page: the transformation may happen dynamically either on the client or on the server, or it may be done as part of the publishing process.
Split into simpler sentences: XSLT is often used to convert XML data into HTML or XHTML documents for display as a web page. The transformation may happen dynamically either on the client or on the server, or it may be done as part of the publishing process.