Distributed_demo is a project mainly written in Ruby, it's free.
The code for the demo at my Scottish Ruby Conf talk
This is the complete code for my Scottish Ruby Conference talk. It demonstrates the idea of having a website generated by multiple distinct and distributed services. For the purposes of the demo, we have a server application which assigns roles to computers that connect. In reality, you'd probably have a legitimate proxy server sit in front of the clusters of nodes...
In our case though, we keep a list of clients that are connected, and which roles they've been assigned to. When we want to generate a page, we determine which roles are necessary, pick one of the clients from each role at random, and use Nginx to combine the results into a single page.
ruby client.rb 1.2.3.4:9876
nginx -c /path/to/distributed_demo/nginx/nginx.conf ruby server.rb 9876
Cheers,
Tyler