Validation of XML data interchange documents with normative schemas using free, open-source software (XML Explorer)

One of the objectives of the US Geoscience Information Network (USGIN) is to establish a community of practice for developing, documenting, adopting, and using standard document encoding for data interchange. The technology for encoding schemes is evolving continuously, and current practice is to use XML encoding with data schema defined by XML schema.

The beginnings of a list of geospatially enabled data and metadata protocols, services, standards, and profiles we are getting exposed to. Please, comment with corrections and additions.