Processing.js demonstration (server included) using zappa, coffeekup and node.js in 30 (!) lines of code

zappa-processing.coffee

require('zappa') ->
  @get '/': -> @render 'index', layout: no
  @view index: ->
    doctype 5
    html ->
      head ->
        title 'Zappa + CoffeeKup + Processing'
        style '''body { background-image:url('http://icanhasnoise.com/1d0b07-4a2219/40x1500/4'); text-align: center; } header { font-family: 'Lobster Two', cursive; font-size: 28px; color: white; text-shadow: 3px 3px 3px brown; }'''
        link rel: 'stylesheet', href: 'http://fonts.googleapis.com/css?family=Lobster+Two&v2'
        script src: 'http://processingjs.org/content/download/processing-js-1.3.6/processing-1.3.6-api.min.js'
        coffeescript ->
          pjsDraw = (pjs) ->
            pjs.setup = ->
              pjs.size 600, 600
              pjs.smooth()
              pjs.noStroke()
              @max_distance = pjs.dist 0, 0, pjs.width, pjs.height
            pjs.draw = ->
              pjs.background 0, 0, 0, 0
              for i in [0..pjs.width] by 40
                for j in [0..pjs.height] by 40
                  size = (pjs.dist pjs.mouseX, pjs.mouseY, i, j) / @max_distance * 132
                  pjs.fill i * 0.4, 50 + size * 2, j * 0.4
                  pjs.ellipse i, j, size, size
          window.onload = ->
            canvas = document.getElementById 'drawCanvas'
            processing = new Processing canvas, pjsDraw
      body ->
        header -> h1 'Zappa + CoffeeKup + Processing'
        canvas id: 'drawCanvas'

Here's a picture of the generated page and the interactive processing canvas: