pycsw is an OGC CSW server implementation written in Python.  pycsw implements clause 10 (HTTP protocol binding (Catalogue Services for the Web, CSW)) of the OpenGIS Catalogue Service Implementation Specification, version 2.0.2. Initial development started in 2010 (more formally announced in 2011).  pycsw allows for the publishing and discovery of geospatial metadata. Existing repositories of geospatial metadata can be exposed via OGC:CSW 2.0.2.  pycsw is Open Source, released under an MIT license, and runs on all major platforms (Windows, Linux, Mac OS X).  Please read the docs at http://pycsw.org/docs for more information.