Guzzle, an extensible PHP HTTP client
PHP Curl Class makes it easy to send HTTP requests and integrate with web APIs
HTTPlug, the HTTP client abstraction for PHP
Requests for PHP is a humble HTTP request library. It simplifies how you interact with other sites and takes away all your worries.
A Chainable, REST Friendly, PHP HTTP Client. A sane alternative to cURL.
Common HTTP Client implementations and tools for HTTPlug
Unirest in PHP: Simplified, lightweight HTTP client library.
Simple handler system used to power clients and servers in PHP (this project is no longer used in Guzzle 6+)