CURL is already installed on your server. It is what you use to communicate with payment providers for checkout.
You just have to use the code to invoke it from php... something like:
$ch = curl_init("http://www.example.com/");
$fp = fopen("example_homepage.txt", "w");
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);