Embedding another application with Express

app.js

var express = require('express')

var app = express.createServer()

// Configuration
app.configure(function() {
  this.set('views', __dirname + '/views')
      .set('view engine', 'jade')
      .use(express.static(__dirname + '/public'))
      .set('view options', {title: 'Express'})
})
.configure('development', function(){
  this.use(express.errorHandler({ dumpExceptions: true, showStack: true }))
})
.configure('production', function(){
  app.use(express.errorHandler())
})

// Routes
app.get('/', function(req, res){
  res.render('index');
})

// Sub-application
app.use('/forum', require('forum').set('view options', {
  title:   app.set('view options').title,
  layout:  app.set('views') + '/layout.' + app.set('view engine'),
  rootUrl: '/forum/'
}))

// Start server
app.listen(8080);
console.log("Express server listening on port %d", app.address().port);

index.jade

h1= title
p Welcome to #{title}
p
  a(href="/forum") Forum

layout.jade

!!!
html
  head
    title= title
    link(rel='stylesheet', href='/stylesheets/style.css')
  body!= body