Apache XML Commons provides an Apache-hosted set of SAX, DOM, StAX and JAXP interfaces for use in other xml-based projects. It is also home to the XML Commons Resolver, a component which can be used in a wide variety of XML parsing, processing and related programs to resolve various public or system identifiers into accessible URLs for use by your application. The resolver supports several catalog types for mapping, including OASIS XML, OASIS TR 9401 and XCatalog styles.