Neon is an HTTP/1.1 and WebDAV client library, with a C interface.

Features:

- High-level wrappers for common HTTP and WebDAV operations
  (GET, MOVE, DELETE, etc)
  Low-level interface to the HTTP request/response engine,
  allowing the use of arbitrary HTTP methods, headers, etc.
- Authentication support including Basic and Digest support,
  along with GSSAPI-based Negotiate on Unix, and SSPI-based
  Negotiate/NTLM on Win32
- SSL/TLS support using OpenSSL or GnuTLS;
  exposing an abstraction layer for verifying server certificates,
  handling client certificates, and examining certificate properties.
- Smartcard-based client certificates are also supported via a
  PKCS#11 wrapper interface
- Abstract interface to parsing XML using libxml2 or expat,
  and wrappers for simplifying handling XML HTTP response bodies
- WebDAV metadata support;
  wrappers for PROPFIND and PROPPATCH to simplify property manipulation