Zato is an Enterprise Service Bus (ESB) and app server written by pragmatists for pragmatists. It provides an HA load-balancer, hot-deployment, and hot-reconfiguration almost everywhere (forget server restarts). It has a browser-based GUI, CLI, and API (forget XML configuration). It supports many protocols, industry standards, and data formats, including HTTP, JSON, SOAP, REST, AMQP, JMS WebSphere MQ, ZeroMQ, Redis, SQL, and FTP.
Magento API Client is a PHP client library for the Magento SOAP API v2. It supports the Mage_Catalog, Mage_CatalogInventory, Mage_Checkout, Mage_Customer, Mage_Directory, Mage_Sales, Enterprise_CustomerBalance, Enterprise_CustomerGiftCard, Mage_GiftMessage, Mage_Core, and Store_View modules. The library uses namespaces and is based on composer tools.