Pushup

From PushupWiki

Pushup - HTTP streaming daemon

Pushup is very fast, efficient and simple HTTP streaming (also known as COMET) daemon. It is written in C++, and it works on *NIX platforms (actually only Linux is supported, *BSD and Solaris support is planned). Basically, it allows you to remotely call Javascript functions in user browser.

HTTP streaming pattern allows you to send data directly to a selected user (or whole group of them) of your web application. It also gives you the possibility to almost instant update of web page content, without needless bandwidth usage caused by continuous polling. This technique gives you opportunity to write real-time web applications, like live chats, web games or instant messaging clients without using such heavy technologies like java, flash or dreaded continuous polling.

Pushup is a stand-alone application, so it does not depend on any web application technology and can be easily integrated with any existing application.

Additionally, Pushup is fast and efficient like hell :).

Download the latest version here.