It actually works perfectly, can you believe it? Inspired by coffeekup.

smallestTemplateEngineEver.coffee

# 21 lines, gutter at 80, for a fully functional coffeescript templater.
global.compiledHTML = ''
makeTagFunc = (tagName, isSelfClosing) ->
  (args...) ->
    selfEndingTag = if isSelfClosing then ' /' else ''
    attrs = args.filter((i) -> typeof i is 'object').reduce(((i, j) ->
      i + ("#{key}='#{val}'" for key, val of j).join ' '), '')
    inner = args.filter((i) ->
      typeof i != 'function' and typeof i != 'object').map((i) -> i).join ' '
    global.compiledHTML += "<#{(tagName + ' ' + attrs).trim()}#{selfEndingTag}>"
    args.filter((i) -> typeof i is 'function').forEach (i) -> i()
    if !selfEndingTag then global.compiledHTML += "#{inner}</#{tagName}>"
'a abbr address area/ article aside audio b base/ bdi bdo blockquote body br/
 button canvas caption cite code col colgroup command data datagrid datalist dd
 del details dfn div dl dt em embed eventsource fieldset figcaption figure
 footer form h1 h2 h3 h4 h5 h6 head header hgroup hr/ html i iframe img/ input/
 ins kbd keygen label legend li link/ mark map menu meta/ meter nav noscript
 object ol optgroup option output p param pre progress q ruby rp rt s samp
 script section select small source span strong style sub summary sup table
 tbody td textarea tfoot th thead time title tr track u ul var video wbr'
  .split(' ').forEach (i) ->
    global[i.replace '/', ''] = makeTagFunc i.replace('/', ''), !!~i.indexOf '/'

# test time!
desc = 'hello'
path = '/asd'
user =
  role: 'vip'
max = 5
random = 'ok go'
shoutify = (word) -> "Yo! #{word}"

html ->
  head ->
    meta charset: 'utf-8'
    title "#{user.role or 'Untitled'} | My awesome website"
    meta name: 'description', content: desc if desc?
    link rel: 'stylesheet', href: '/stylesheets/app.css'
    style '''
      body {font-family: sans-serif}
      header, nav, section, footer {display: block}
    '''
    script src: '/javascripts/jquery.js'
  body ->
    header ->
      h1 random or 'Untitled', 'hahaha'
      nav ->
        ul ->
          (li -> a href: '/', 'Home') unless path is '/'
          li ->
            a href: '/chunky', 'Bacon!'
          switch user.role
            when 'owner', 'admin'
              li -> a href: '/admin', 'Secret Stuff'
            when 'vip'
              li -> a href: '/vip', 'Exclusive Stuff'
            else
              li -> a href: '/commoners', 'Just Stuff'
    section ->
      h2 "Let's count to #{max}:"
      for i in [1..max]
        p i
    footer ->
      p shoutify('bye')

console.log global.compiledHTML