NanoHttpd is a lightweight HTTP server designed for embedding in other applications. It's only one Java file, in two "flavors", one strictly Java 1.1 compatible, and one at "current" standards. It supports GET, POST, PUT, HEAD and DELETE requests, and supports file uploading with very small memory overhead. Temp file usage and the threading model are easily customized.
RestyGWT is a GWT generator for REST services and JSON encoded data transfer objects. RestyGWT Rest Services allow you to define an asynchronous service API which is then implemented via GWT deferred binding by RestyGWT. It features generation of asynchronous RESTful JSON based service proxies, encoding and decoding of Java objects to JSON, and an easy-to-use REST API.
PSX is a PHP framework for creating RESTful APIs. It helps you to build clean URLs serving Web standard formats like JSON, XML, Atom, and RSS. It includes a handler system that abstracts away SQL queries from domain logic, a routing system that executes correct controller method for the location of the controller and the method annotation, and a flexible data system that converts database records into formats like JSON, XML, Atom, and RSS. A lightweight DI container handles dependencies. The controller supports request and response filters that can modify the HTTP request or response, and filters are provided for Basic and Oauth authentication.