cURL library - where can I get?

Guzzle 6 requires PHP 5.5. It is easy to be installed with Composer. But it needs to load some files immediately, so on PHP 5.3 it will cause PHP parsing error nevertheless you use this component or not.

Requests 1.6.1 requires PHP 5.2. It is lighter. For those who use the Curl library before and the Rest client library by Phil Sturgeon, Requests would be more familiar. It can be installed with Composer, I have chosen a manual installation, it is possible.