Guzzle is a PHP HTTP client and framework for building RESTful web service clients

A bundle integrating Guzzle >=4.0 in Symfony

Behat API extension using Guzzle Service Descriptions to functionally test API endpoints

Segment.io PHP Library - using Guzzle 4

PHP OAuth 1/2 service classes using Guzzle

A Guzzle plugin that let's you debug everything in the Clockwork browser extension.