Not even sure if it would easily work but for an upcoming project I may need to set up a web sockets only server, it would not have a database, memcache or even serve static files, all it would need to do is work some logic and update other clients.
The server may need to support 1~300000 clients simultaneously so Node.js+NginX makes sense, but maybe not all the other features of a traditional web server (apache for example) are necessary...
Something like Minix sounds like it would work...