Geoserver is a fully functional open source WFS-T and WMS server that follows the OGC open standards.
karlUshi: "With Geoserver you can publish data as maps/images (using the WMS), as actual data (using the WFS), and allow users to update, delete, and insert features (using the WFS-T). GeoServer's focus is ease of use and support for open standards, in order to enable anyone to quickly share their geospatial information in an interoperable way."