Here is a list of available metadata tools from the US Federal Geographic Data Committee.
Further FOSS metadata tools:
- GeoNetwork (OSGeo project) - "GeoNetwork opensource implements both the Portal component and the Catalog database of a Spatial Data Infrastructure (SDI) defined in the OGC Reference Architecture. It provides tools for managing and publishing metadata on spatial data and related services."
- Mapbender (OSGeo project) - Mapbender is a geoportal framework to manage standard map and feature services providing all tools needed for manage and publish associated metadata. Additionally Mapbender offers to create, maintain and publish virtual OGC WMS Capabilities documents, monitor services, and forward dynamically modified Capabilities documents through security proxies including user management and fine grained permission.
- MDweb - "MDweb is a generic, multi-language, multi-standard, multi-platform tool for cataloging and locating environmental information, and, by extension, geographical data. [...] The specifications adopted for the cataloging of geographical information are based on the ISO 19115 standard and conform to Open Geospatial Consortium specifications and European directives (INSPIRE directives)."
- MEtadata Editor (MEE™) is a powerful tool that create, edit and optimize metadata files in ISO19115, ISO19139 standard
- CatMDEdit is a metadata editor tool that facilitates the documentation of resources, with special focus on the description of geographic information resources.
- DCLite4G: simple method of representing some properties of geographic data sets. The vocabulary is defined in RDF and OWL. Example
- MIG EDITOR The MIG Editor is a geographical metadata editor that implements a subset of the 19115, 19119 and 19139 ISO formats. Based in the Portuguese Metadata Profile and INSPIRE requirements.
Luca Casagrande commented:
"Don't know if this can help, but here: http://www.jornadasgvsig.gva.es/fileadmin/conselleria/Documentacion/3asJornadas/sesiones/sesion4/Gestion_metadatos_en_gvSIG.pdf
You can find the paper of "Semiautomatic extraction and management of metadata in gvSIG" presented during latest gvSIG conference."