Mongrel2 is an open-source "language agnostic" web server

Web server

Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....

 written by Zed Shaw

Zed Shaw

Zed A. Shaw is a writer, software developer, and musician, most commonly known for creating the Mongrel web server for Ruby web applications, as well as his unconventional and sometimes controversial articles on technology, business, and technical communities...

, and is the successor to Shaw's Mongrel server. The server supports HTTP, Flash

Adobe Flash

Adobe Flash is a multimedia platform used to add animation, video, and interactivity to web pages. Flash is frequently used for advertisements, games and flash animations for broadcast...

 XMLSocket

XMLSocket

XMLSocket is a class in ActionScript which allows Adobe Flash content to use socket communication, via TCP stream sockets. It can be used for plain text, although, as the name implies, it was made for XML...

s, WebSockets

WebSockets

WebSocket is a technology providing for bi-directional, full-duplex communications channels, over a single Transmission Control Protocol socket. It is designed to be implemented in web browsers and web servers, but it can be used by any client or server application...

 and long polling connections.

Language agnostic

Mongrel2 is described as language agnostic, meaning it does not prefer any specific programming language over another. The server's documentation says:

Development

Shaw began working on the server in June 2010 and released version 1.0 of the software on September 1, 2010. Mongrel2 has nothing in common with the original Mongrel webserver, except for using the same HTTP parser.