Flickcurl is a C library for calling the Flickr Web service API. It handles the API signing, token management, and parameter encoding and decoding, resulting in C functions for the Web services APIs. It uses libcurl to call the REST Web service, and libxml2 to manipulate the XML responses. The library supports reading photo, tag, and comments information, the photo upload and searching APIs, and writing tags and comments. It provides utilities such as "flickcurl" to exercise the API and "flickrdf" to get RDF metadata descriptions out of photos, tags, and machine tags.