Daniel Stenberg leads the Curl project, which aims to handle interpreting URLs and fetching data from them. PHP uses the Curl library to provide this functionality to your scripts. A typical session involves creating a Curl resource with curl_init, setting options with curl_setopt, and executing the request with curl_exec. Instead of a large set of functions, the Curl extension uses a small set of functions paired with a large set of constants used with curl_setopt.
You can learn more about Curl at its home page: <http://curl.haxx.se/>.
Recently, the Curl project added the so-called multi-interface. PHP includes support for these functions, but keep in mind their relative newness.
Use curl_close to free ...