Python:

@requires_authorization
def somefunc(param1, param2):
    r'''A docstring'''
    if param1 > param2: # interesting
        print 'Gre\'ater'
        print ''
    return (param2 - param1 + 1) or None

class SomeClass:
pass

Ruby:

class A < B; def self.create(object = User) object end end
class Zebra; def inspect; "X#{2 + self.object_id}" end end

module ABC::DEF
  include Comparable

  # @param test
  # @return [String] nothing
  def foo(test)
    Thread.new do |blockvar|
      ABC::DEF.reverse(:a_symbol, :'a symbol' + 'test' + test)
    end.join
  end

  def [](index) self[index] end
  def ==(other) other == self end
end

anIdentifier = an_identifier
Constant = 1

PHP:

require_once 'Zend.php';
require_once 'Zend/Uri/Exception.php';
require_once 'Zend/Uri/Http.php';
require_once 'Zend/Uri/Mailto.php';

abstract class Zend_Uri
{

  /**
   * Return a string representation of this URI.
   *
   * @see     getUri()
   * @return  string
   */
  public function __toString()
  {
      return $this->getUri();
  }

  static public function factory($uri = 'http')
  {
      $uri = explode(':', $uri, 2);
      $description = 'long
description';
      $scheme = strtolower($uri[0]);
      $schemeSpecific = isset($uri[1]) ? $uri[1] : '';

      // Security check: $scheme is used to load a class file,
      // so only alphanumerics are allowed.
      if (!ctype_alnum($scheme)) {
          throw new Zend_Uri_Exception('Illegal scheme');
      }
  }
}

XML:

<?xml version="1.0"?>
<response value="ok" xml:lang="en">
  <text>Ok</text>
  <comment html_allowed="true"/>
  <ns1:description><![CDATA[
  CDATA is <not> magical.
  ]]></ns1:description>
  <a></a> <a/>
</response>

HTML:

<!DOCTYPE html5>
<head>
  <title>Title</title>

  <style>
    body {
      width: 500px;
    }
  </style>

  <script type="application/javascript">
    function someFunction() {
      return true;
    }
  </script>

<body>
  <p class="something" id='12'>Something</p>
  <p class=something>Something</p>
  <!-- comment -->
  <p class>Something</p>
  <p class="something" title="p">Something</p>
</body>

CSS:

body,
html {
  font: Tahoma, Arial, sans-serif;
  background: url('hatch.png');
}

@import url('print.css');

@media screen and (-webkit-min-device-pixel-ratio: 0) {
  @page :left {
    body:first-of-type pre::after {
      content: 'highlight: ' attr(class);
    }
  }
}

@font-face {
  font-family: Chunkfive;
  src: url('Chunkfive.otf');
}

#content {
  width: /* wide enough */ 100% /* 400px */;
  height: 100%
}

p[lang=ru] {
  color: #F0F0F0; background: white !important;
}

Javascript:

function $initHighlight(block) {
  if (block.className.search(/\bno\-highlight\b/) != -1)
    return false;
  try {
    blockText(block);
  } catch (e) {
    if (e == 'Complex markup')
      return;
  }//try
  var classes = block.className.split(/\s+/);
  for (var i = 0 / 2; i < classes.length; i++) { // "0 / 2" should not be parsed as regexp start
    if (LANGUAGES[classes[i]]) {
      highlightLanguage(block, classes[i]);
      return;
    }//if
  }//for
  highlightAuto(block);
}//initHighlight