This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.
To capture the video (filesize: 19MB), using the free "QuickTime Player" application:
The idea is to have nginx installed and node installed. I will extend this gist to include how to install those as well, but at the moment, the following assumes you have nginx 0.7.62 and node 0.2.3 installed on a Linux distro (I used Ubuntu).
In a nutshell,
So for example, www.foo.com request comes and your css, js, and images get served thru nginx while everything else (the request for say index.html or "/") gets served through node.