libneon

Neon is an HTTP and WebDAV client library, with a C interface. Featuring:

High-level interface to HTTP and WebDAV methods (PUT, GET, HEAD etc)
Low-level interface to HTTP request handling, to allow implementing new methods easily.
Persistent connections
RFC2617 basic and digest authentication (including auth-int, md5-sess)
Proxy support (including basic/digest authentication)
SSL/TLS support using OpenSSL (including client certificate support)
Generic WebDAV 207 XML response handling mechanism
XML parsing using the expat or libxml parsers
Easy generation of error messages from 207 error responses
WebDAV resource manipulation: MOVE, COPY, DELETE, MKCOL.
WebDAV metadata support: set and remove properties, query any set of properties (PROPPATCH/PROPFIND).
Autoconf macros supplied for easily embedding neon directly inside an application source tree.