Xerces

Xerces is a name used for several subjects in biology, computing, and conservation. The most famous is the Xerces blue butterfly, Glaucopsyche xerces, an extinct species once native to the coastal dunes and grasslands around the San Francisco Bay Area. Habitat loss and urban development led to its decline; the species disappeared by the early 1940s, with the last widely reported sightings around 1930s–1941. The name Xerces has since been used as a memorial in conservation contexts, most notably by the Xerces Society for Invertebrate Conservation.

In computing, Xerces refers to the Apache Xerces family of open-source XML parsers. Implemented primarily as Xerces-C++ and Xerces-J, the libraries provide DOM and SAX APIs for parsing, validating, and processing XML documents, including support for XML Schema and other standards. Maintained by the Apache Software Foundation, Xerces is widely used in both commercial and open-source software across multiple platforms and languages.

The Xerces Society for Invertebrate Conservation is a nonprofit organization based in Portland, Oregon. It advocates for invertebrate conservation, conducts research, and runs education and citizen-science programs. The organization chose the name in reference to the Xerces blue butterfly; it seeks to preserve other imperiled invertebrates and their habitats.