Rack + Javascript = Jack
Write your web apps in the same powerful language on both ends.
Yes, thanks entirely to the hard work of Christian Neukirchen for Rack and John Barnette, Aaron Patterson, Yehuda Katz, and Matthew Draper for their work on Johnson.
Because this is kickass, that's why:
function(env){
return [200, {'Content-Type': 'text/html'}, "you're looking at: "+env['PATH_INFO']];
};
$ sudo gem install jbarnette-johnson --source=http://gems.github.com
$ git clone git://github.com/JackDanger/jack.git # or one of the forks
$ cd jack && rake install_gem
[...]
$ samples/hello.js &
$ curl http://localhost:1337
First version (and idea) by Jack Danger Canty, this version by Phil Hagelberg.