GNU libmicrohttpd is a small C library for embedding HTTP server functionality into other applications. It is reentrant, fast, supports HTTP 1.1, and permits listening on multiple ports. The API is simple and still powerful enough to allow programmers to use the entire HTTP feature set. SSL/TLS support is available as an option.
Restlet is a REST framework for Java. It supports all REST concepts (Resource, Representation, Connector, Component, etc.) and is suitable for both client and server Web applications. It supports major Web standards like HTTP, SMTP, XML, JSON, WADL, and Atom. Many extensions are also available to integrate with Servlet, Spring, Jetty, Grizzly, Simple, JAXB, JAX-RS, JiBX, Velocity, or FreeMarker. A GWT version is also available.
Tntnet is a Web application server for generating Web applications in C++. HTML pages with some additional tags for inclusion of C++ code are compiled into shared libraries and served from tntnet. It resembles PHP, JSP, or Mason, but the programming language used is C++, and the pages are compiled into native code before serving. Tntnet is fully multithreaded and supports HTTP keep-alive for best performance. Its dynamic pages are faster than static pages with other Web servers, while creating Web applications is simple.
Embedded HTTP Server (EHS) is a C++ class which can be inherited from to give HTTP server functionality to any class or application. It supports form data via POST or GET, setting and reading cookies, and uploads via multi-part form attachments. It is useful for adding Web-based administration or statistics to any C++ program. It also supports HTTPS for doing secure transactions.
jo! is a pure Java Web server that implements the Servlet API, JSP, and HTTP/1.1. It features advanced thread management, virtual hosts, memory-sensitive file cache, authentication using a role abstraction, automatic compressed transfer of text or HTML files, auto internationalization, auto servlet and JSP reloading, auto reload of WARs, hot deployment of WARs, JSR-45 support, and an easy-to-use Swing console.
ulxmlrpcpp is a library to perform calls via XML-RPC in an object oriented approach. It is possible to create both client and server applications in multithreaded environments. Unlike other implementations, it does not insist on HTTP for transportation, but might also accept other ways (e.g. a simple serial line with a user-defined protocol). For HTTP as a transportation protocol, the following features are supported: cookies, SSL/TLS, proxy, SSL/TLS over a proxy, and chunked transfers. ulxmlrpcpp is also able to transmit data faster with binary XML.