Xcerpt is a declarative, rule-based query and
transformation language for XML, inspired by logic
programming. Instead of the path-based
navigational approach taken by languages like XSLT
and XQuery, Xcerpt uses pattern-based, positional
queries, where a pattern is an "example" of the
database containing variables for binding content.
As in logic programming, rules may be chained to
form more complex queries.
