Example: record database

record in database in XML and XSLT transforms, make it easy to process the database in different ways:
Output the data: HTML (music2html.xsl) XSL-FO (PDF) (music2fo.xsl). Many things shown: sorting, grouping, indexing, etc.

Query the data:

<xsl:apply-templates select="collection/record[@year='1971']/artist"/>

returns

Genesis
Aphrodite's Child
Emerson, Lake and Palmer
Pink Floyd