Class that implements requests to Web resources using the HTTP protocol.

It features:
- May submit HTTP requests with any method, to any page, to any server, connecting to any port.
- Provides support to setup connection and request arguments from a given URL.
- May submit requests via a proxy server with support for authentication if necessary.
- Supports HTTP direct access or proxy based authentication mechanisms via SASL class library like HTTP Basic, HTTP Digest or NTLM (Windows or Samba).
- Support secure connections (https) via Curl library with SSL support, or at least PHP 4.3.0 with OpenSSL support, or via a non-SSL HTTP proxy server.
- Supports accessing secure pages using SSL certificates and private keys using Curl library
- Supports user defined request headers.
- Supports POST requests with a user defined array of form values.
- Supports POST requests with a user defined request bodies for instance for making requests to SOAP services.
- Supports requests to sites hosting virtual Web servers.
- Retrieves the HTTP response headers and body data separately.
- Support HTTP 1.1 chunked content encoding
- Supports session and persistent cookies.
- Provides optional handling of redirected pages.
- Supports defining connection and data transfer timeout values.
- Can output connection debug information in plain text or formatted as HTML.
- An add-on class is provided to login to Yahoo sites and perform actions on the behalf of the logged users like exporting the user address book or sending invitation to a group.