Pax URL is a set of OSGi URL Handlers Service implementations as follows:

classpath: protocol handler. Provides access to classpath resources from your bundle or other bundles installed.
mvn: protocol handler. Provide access to maven repository artifacts based on the well known groupId, artifactId, version and type
obr: protocol handler. Make use of OBR bundle repository.
war:/war-i: protocol handlers. Automates war deployment.
wrap: protocol handler. Wraps "classic" jars as OSGi bundles.