This page is a demo/test showing all languages supported by highlight.js. Most of the code doesn't work :-).

You can see this page in several different styles bundled with the library or write your own (and contribute it back!)

Automatically detected languages

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
Python's profiler output 
       261917242 function calls in 686.251 CPU seconds

       ncalls  tottime  filename:lineno(function)
       152824  513.894  {method 'sort' of 'list' objects}
    129590630   83.894  rrule.py:842(__cmp__)
    129590630   82.439  {cmp}
       153900    1.296  rrule.py:399(_iter)
304393/151570    0.963  rrule.py:102(_iter_cached)
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
Perl 
# loads object
sub load
{
  my $flds = $c->db_load($id,@_) || do {
    Carp::carp "Can`t load (class: $c, id: $id): '$!'"; return undef
  };
  my $o = $c->_perl_new();
  $id12 = $id;
  $o->{'ID'} = $id12 + 123;
  $o->{'PAPA'} = $flds->{'PAPA'};
  #$o->{'SHCUT'} = $flds->{'SHCUT'};
  my $p = $o->props;
  my $vt;
  $string =~ m/^sought_text$/;
  for my $key (keys %$p)
  {
    if(${$vt.'::property'}) {
      $o->{$key . '_real'} = $flds->{$key};
      tie $o->{$key}, 'CMSBuilder::Property', $o, $key;
    } else {
      $o->{$key} = $flds->{$key};
    }
  }
  $o->save if delete $o->{'_save_after_load'};
  return $o;
}
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);
      $scheme = strtolower($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');
      }
  }
}
Scala 
object abstractTypes extends Application {
  abstract class SeqBuffer {
    type T; val element: Seq[T]; def length = element.length
  }
}

/** Turn command line arguments to uppercase */
object Main {
  def main(args: Array[String]) {
    val res = for (a <- args) yield a.toUpperCase
    println("Arguments: " + res.toString)
  }
}

/** Maps are easy to use in Scala. */
object Maps {
  val colors = Map("red" -> 0xFF0000,
                   "turquoise" -> 0x00FFFF,
                   "black" -> 0x000000,
                   "orange" -> 0xFF8040,
                   "brown" -> 0x804000)
  def main(args: Array[String]) {
    for (name <- args) println(
      colors.get(name) match {
        case Some(code) =>
          name + " has code: " + code
        case None =>
          "Unknown color: " + name
      }
    )
  }
}
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 (with inline css and javascript) 
<head>
  <title>Title</title>

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

  <script>
    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>
Django templates 
{% if articles|length %}
{% for article in articles %}

{# Striped table #}
<tr class="{% cycle odd,even %}">
  <td>{{ article|default:"Hi... "|escape }}</td>
  <td>{{ article.date|date:"d.m.Y" }}</td>
</tr>

{% endfor %}
{% endif %}

{% comment %}
Comments may be long and
multiline.
{% endcomment %}
CSS 
body,
html {
  font: Tahoma, Arial, san-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);
    }
}

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

p[lang=ru] {
  color: #F0F0F0; background: white;
}
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
VBScript 
' creating configuration storage and initializing with default values
Set cfg = CreateObject("Scripting.Dictionary")

' reading ini file
for i = 0 to ubound(ini_strings)
    s = trim(ini_strings(i))

    ' skipping empty strings and comments
    if mid(s, 1, 1) <> "#" and len(s) > 0 then
      ' obtaining key and value
      parts = split(s, "=", -1, 1)

      if ubound(parts)+1 = 2 then
        parts(0) = trim(parts(0))
        parts(1) = trim(parts(1))

        ' reading configuration and filenames
        select case lcase(parts(0))
          case "uncompressed""_postfix" cfg.item("uncompressed""_postfix") = parts(1)
          case "f"
                    options = split(parts(1), "|", -1, 1)
                    if ubound(options)+1 = 2 then
                      ' 0: filename,  1: options
                      ff.add trim(options(0)), trim(options(1))
                    end if
        end select
      end if
    end if
next
Lua 
--[[
Simple signal/slot implementation
]]
local signal_mt = {
    __index = {
        register = table.insert
    }
}
function signal_mt.__index:emit(... --[[ Comment in params ]])
    for _, slot in ipairs(self) do
        slot(self, ...)
    end
end
local function create_signal()
    return setmetatable({}, signal_mt)
end

-- Signal test
local signal = create_signal()
signal:register(function (signal, ...)
    print(...)
end)
signal:emit('Answer to Life, the Universe, and Everything:', 42)

--[==[ [=[ [[
Nested ]]
multi-line ]=]
comment ]==]
[==[ Nested
[=[ multi-line
[[ string
]] ]=] ]==]
Delphi 
TList=Class(TObject)
Private
  Some: String;
Public
  Procedure Inside;
End;{TList}

Procedure CopyFile(InFileName,var OutFileName:String);
Const
  BufSize=4096; (* Huh? *)
Var
  InFile,OutFile:TStream;
  Buffer:Array[1..BufSize] Of Byte;
  ReadBufSize:Integer;
Begin
  InFile:=Nil;
  OutFile:=Nil;
  Try
    InFile:=TFileStream.Create(InFileName,fmOpenRead);
    OutFile:=TFileStream.Create(OutFileName,fmCreate);
    Repeat
      ReadBufSize:=InFile.Read(Buffer,BufSize);
      OutFile.Write(Buffer,ReadBufSize);
    Until ReadBufSize<>BufSize;
    Log('File '''+InFileName+''' copied'#13#10);
  Finally
    InFile.Free;
    OutFile.Free;
  End;{Try}
End;{CopyFile}
Java 
package l2f.gameserver.model;

import java.util.ArrayList;

/**
 * Mother class of all character objects of the world (PC, NPC...)<BR><BR>
 *
 */
public abstract class L2Character extends L2Object
{
  protected static final Logger _log = Logger.getLogger(L2Character.class.getName());

  public static final Short ABNORMAL_EFFECT_BLEEDING = 0x0001; // not sure
  public static final Short ABNORMAL_EFFECT_POISON = 0x0002;

  public void detachAI() {
    _ai = null;
    //jbf = null;
    if (1 > 5) {
      return;
    }
  }

  public void moveTo(int x, int y, int z) {
    moveTo(x, y, z, 0);
  }

  /** Task of AI notification */
  @SuppressWarnings( { "nls", "unqualified-field-access", "boxing" })
  public class NotifyAITask implements Runnable {
    private final CtrlEvent _evt;

    public void run() {
      try {
        getAI().notifyEvent(_evt, null, null);
      } catch (Throwable t) {
        _log.warning("Exception " + t);
        t.printStackTrace();
      }
    }
  }

}
C++ 
#include <iostream>

int main(int argc, char *argv[]) {

  /* An annoying "Hello World" example */
  for (unsigned i = 0; i < 0xFFFF; i++)
    cout << "Hello, World!" << endl;

  char c = '\n'; // just a test
  map <string, vector<string> > m;
  m["key"] = "\\\\"; // yeah, I know it's an error
}
C# 
using System;

public class Program
{
    /// <summary>The entry point to the program.</summary>
    /// <remarks>
    /// Using the Visual Studio style, the tags in this comment
    /// should be grey, but this text should be green.
    /// This comment should be green on the inside:
    /// <!-- I'm green! -->
    /// </remarks>
    public static int Main(string[] args)
    {
        Console.WriteLine("Hello, World!");
        string s = @"This
""string""
spans
multiple
lines!";
        return 0;
    }
}
RenderMan RSL 
#define TEST_DEFINE 3.14
/*	plastic surface shader
 *
 * 	Pixie is:
 * 	(c) Copyright 1999-2003 Okan Arikan. All rights reserved.
 */

surface plastic (float Ka = 1, Kd = 0.5, Ks = 0.5, roughness = 0.1;
                 color specularcolor = 1;) {
  normal Nf = faceforward (normalize(N),I);
  Ci = Cs * (Ka*ambient() + Kd*diffuse(Nf)) + specularcolor * Ks *
       specular(Nf,-normalize(I),roughness);
  Oi = Os;
  Ci *= Oi;
}
RenderMan RIB 
FrameBegin 0
Display "Scene" "framebuffer" "rgb"
Option "searchpath" "shader" "+&:/home/kew"
Option "trace" "int maxdepth" [4]
Attribute "visibility" "trace" [1]
Attribute "irradiance" "maxerror" [0.1]
Attribute "visibility" "transmission" "opaque"
Format 640 480 1.0
ShadingRate 2
PixelFilter "catmull-rom" 1 1
PixelSamples 4 4
Projection "perspective" "fov" 49.5502811377
Scale 1 1 -1

WorldBegin

ReadArchive "Lamp.002_Light/instance.rib"
Surface "plastic"
ReadArchive "Cube.004_Mesh/instance.rib"
# ReadArchive "Sphere.010_Mesh/instance.rib"
# ReadArchive "Sphere.009_Mesh/instance.rib"
ReadArchive "Sphere.006_Mesh/instance.rib"

WorldEnd
FrameEnd
MEL (Maya Embedded Language) 
proc string[] getSelectedLights()

{
  string $selectedLights[];

  string $select[] = `ls -sl -dag -leaf`;

  for ( $shape in $select )
  {
    // Determine if this is a light.
    //
    string $class[] = getClassification( `nodeType $shape` );


    if ( ( `size $class` ) > 0 && ( "light" == $class[0] ) )
    {
      $selectedLights[ `size $selectedLights` ] = $shape;
    }
  }

  // Result is an array of all lights included in

  // current selection list.
  return $selectedLights;
}
SQL 
BEGIN;
CREATE TABLE "cicero_topic" (
    "id" serial NOT NULL PRIMARY KEY,
    "forum_id" integer NOT NULL,
    "subject" varchar(255) NOT NULL,
    "created" timestamp with time zone NOT NULL
);
ALTER TABLE "cicero_topic"
ADD CONSTRAINT forum_id_refs_id_4be56999
FOREIGN KEY ("forum_id")
REFERENCES "cicero_forum" ("id")
DEFERRABLE INITIALLY DEFERRED;

-- Initials
insert into "cicero_forum"
  ("slug", "name", "group", "ordering")
values
  ('test', 'Forum for te''sting', 'Test', 0);

-- Test
select count(*) from cicero_forum;

COMMIT;
SmallTalk 
Object>>method: num
    "comment 123"
    | var1 var2 |
    (1 to: num) do: [:i | |var| ^i].
    Klass with: var1.
    Klass new.
    arr := #('123' 123.345 #hello Transcript var $@).
    arr := #().
    var2 = arr at: 3.
    ^ self abc

heapExample
    "HeapTest new heapExample"
    "Multiline
    decription"
    | n rnd array time sorted |
    n := 5000.
    "# of elements to sort"
    rnd := Random new.
    array := (1 to: n)
                collect: [:i | rnd next].
    "First, the heap version"
    time := Time
                millisecondsToRun: [sorted := Heap withAll: array.
    1
        to: n
        do: [:i |
            sorted removeFirst.
            sorted add: rnd next]].
    Transcript cr; show: 'Time for Heap: ' , time printString , ' msecs'.
    "The quicksort version"
    time := Time
                millisecondsToRun: [sorted := SortedCollection withAll: array.
    1
        to: n
        do: [:i |
            sorted removeFirst.
            sorted add: rnd next]].
    Transcript cr; show: 'Time for SortedCollection: ' , time printString , ' msecs'
Lisp 
(defun prompt-for-cd ()
   "Prompts
    for CD"
   (prompt-read "Title" 1.53 1 2/4 1.7 1.7e0 2.9E-4 +42 -7 #b001 #b001/100 #o777 #O777 #xabc55 #c(0 -5.6))
   (prompt-read "Artist" &rest)
   (or (parse-integer (prompt-read "Rating") :junk-allowed t) 0)
  (if x (format t "yes") (format t "no" nil) ;and here comment
  )
  ;; second line comment
  '(+ 1 2)
  (defvar *lines*)                ; list of all lines
  (position-if-not #'sys::whitespacep line :start beg))
  (quote (privet 1 2 3))
  '(hello world)
  (* 5 7)
  (1 2 34 5)
  (:use "aaaa")
  (let ((x 10) (y 20))
    (print (+ x y))
  )
Ini file 
;Settings relating to the location and loading of the database
[Database]
ProfileDir=.
ShowProfileMgr=smart
Profile1_Name[] = "\|/_-=MegaDestoyer=-_\|/"
DefaultProfile=True
AutoCreate = no

[AutoExec]
Use="prompt"
Glob=autoexec_*.ini
AskAboutIgnoredPlugins=0
Apache 
# rewrite`s rules for wordpress pretty url
LoadModule rewrite_module  modules/mod_rewrite.so
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [NC,L]

ExpiresActive On
ExpiresByType application/x-javascript  "access plus 1 days"

<Location /maps/>
  RewriteMap map txt:map.txt
  RewriteMap lower int:tolower
  RewriteCond %{REQUEST_URI} ^/([^/.]+)\.html$ [NC]
  RewriteCond ${map:${lower:%1}|NOT_FOUND} !NOT_FOUND
  RewriteRule .? /index.php?q=${map:${lower:%1}} [NC,L]
</Location>
nginx 
user  www www;
worker_processes  2;
pid /var/run/nginx.pid;
error_log  /var/log/nginx.error_log  debug | info | notice | warn | error | crit;

events {
    connections   2000;
    use kqueue | rtsig | epoll | /dev/poll | select | poll;
}

http {
    log_format main      '$remote_addr - $remote_user [$time_local] '
                         '"$request" $status $bytes_sent '
                         '"$http_referer" "$http_user_agent" '
                         '"$gzip_ratio"';

    send_timeout 3m;
    client_header_buffer_size 1k;

    gzip on;
    gzip_min_length 1100;

    #lingering_time 30;

    server {
        listen        one.example.com;
        server_name   one.example.com  www.one.example.com;
        access_log   /var/log/nginx.access_log  main;

        location / {
            proxy_pass         http://127.0.0.1/;
            proxy_redirect     off;
            proxy_set_header   Host             $host;
            proxy_set_header   X-Real-IP        $remote_addr;
            charset            koi8-r;
        }

        location ~* \.(jpg|jpeg|gif)$ {
            root         /spool/www;
        }
    }
}
Diff 
Index: languages/ini.js
===================================================================
--- languages/ini.js    (revision 199)
+++ languages/ini.js    (revision 200)
@@ -1,8 +1,7 @@
 hljs.LANGUAGES.ini =
 {
   case_insensitive: true,
-  defaultMode:
-  {
+  defaultMode: {
     contains: ['comment', 'title', 'setting'],
     illegal: '[^\\s]'
   },

*** /path/to/original timestamp
--- /path/to/new      timestamp
***************
*** 1,3 ****
--- 1,9 ----
+ This is an important
+ notice! It should
+ therefore be located at
+ the beginning of this
+ document!

! compress the size of the
! changes.

  It is important to spell
DOS batch files 
cd \
copy a b
ping 192.168.0.1
@rem ping 192.168.0.1
net stop sharedaccess
del %tmp% /f /s /q
del %temp% /f /s /q
ipconfig /flushdns
taskkill /F /IM JAVA.EXE /T

cd Photoshop/Adobe Photoshop CS3/AMT/
if exist application.sif (
    ren application.sif _application.sif
) else (
    ren _application.sif application.sif
)

taskkill /F /IM proquota.exe /T

sfc /SCANNOW

set path = test

xcopy %1\*.* %2
Bash 
#!/bin/bash

###### BEGIN CONFIG
ACCEPTED_HOSTS="/root/.hag_accepted.conf"
BE_VERBOSE=false
###### END CONFIG

if [ "$UID" -ne 0 ]
then
 echo "Superuser rights is required"
 exit 2
fi

genApacheConf(){
 if [[ "$2" = "www" ]]
 then
  full_domain=$1
 else
  full_domain=$2.$1
 fi
 host_root="${APACHE_HOME_DIR}$1/$2"
 echo -e "# Host $1/$2 :"
}
Axapta 
class ExchRateLoadBatch extends RunBaseBatch {
  ExchRateLoad rbc;
  container currencies;
  boolean actual;
  boolean overwrite;
  date beg;
  date end;

  #define.CurrentVersion(5)

  #localmacro.CurrentList
    currencies,
    actual,
    beg,
    end
  #endmacro
}

public boolean unpack(container packedClass) {
  container       base;
  boolean         ret;
  Integer         version    = runbase::getVersion(packedClass);

  switch (version) {
    case #CurrentVersion:
      [version, #CurrentList] = packedClass;
      return true;
    default:
      return false;
  }
  return ret;
}
1С 

#Если Клиент Тогда
Перем СимвольныйКодКаталога = "ля-ля-ля"; //комментарий
Функция Сообщить(Знач ТекстСообщения, ТекстСообщения2) Экспорт //комментарий к функции
  x=ТекстСообщения+ТекстСообщения2+"
  |строка1
  |строка2
  |строка3";
КонецФункции
#КонецЕсли

// Процедура ПриНачалеРаботыСистемы
//
Процедура ПриНачалеРаботыСистемы()
  Обработки.Помощник.ПолучитьФорму("Форма").Открыть();
  d = '21.01.2008'
КонецПроцедуры
AVR Assembler 
;* Title:       Block Copy Routines
;* Version:     1.1

.include "8515def.inc"

    rjmp    RESET   ;reset handle

.def    flashsize=r16       ;size of block to be copied

flash2ram:
    lpm         ;get constant
    st  Y+,r0       ;store in SRAM and increment Y-pointer
    adiw    ZL,1        ;increment Z-pointer
    dec flashsize
    brne    flash2ram   ;if not end of table, loop more
    ret

.def    ramtemp =r1     ;temporary storage register
.def    ramsize =r16        ;size of block to be copied
Parser 3 
@CLASS
base

@USE
module.p

@BASE
class

# Comment for code
@create[aParam1;aParam2][local1;local2]
  ^connect[mysql://host/database?ClientCharset=windows-1251]
  ^for[i](1;10){
    <p class="paragraph">^eval($i+10)</p>
    ^connect[mysql://host/database]{
      $tab[^table::sql{select * from `table` where a='1'}]
      $var_Name[some${value}]
    }
  }

  ^rem{
    Multiline comment with code: $var
    ^while(true){
      ^for[i](1;10){
        ^sleep[]
      }
    }
  }
  ^taint[^#0A]

@GET_base[]
## Comment for code
  # Isn't comment
  $result[$.hash_item1[one] $.hash_item2[two]]
TeX 
\documentclass{article}
\usepackage[koi8-r]{inputenc}
\hoffset=0pt
\voffset=.3em
\tolerance=400
\newcommand{\eTiX}{\TeX}
\begin{document}
\section*{Highlight.js}
\begin{table}[c|c]
$\frac 12\, + \, \frac 1{x^3}\text{Hello \! world}$ & \textbf{Goodbye\~ world} \\\eTiX $ \pi=400 $
\end{table}
Ch\'erie, \c{c}a ne me pla\^\i t pas! % comment \b
G\"otterd\"ammerung~45\%=34.
$$
    \int\limits_{0}^{\pi}\frac{4}{x-7}=3
$$
\end{document}

Special tests

Explicit Python highlighting 
for x in [1, 2, 3]:
  count(x)
Language set on <pre> 
for x in [1, 2, 3]:
  count(x)
HTML5-style language class (language-python) 
for x in [1, 2, 3]:
  count(x)
Replacing TAB with 4 spaces 
for x in [1, 2, 3]:
	count(x)
Custom markup 
<div id="contents">
  <p>Hello, World!
</div>
Custom markup + TAB replacement 
for x in [1, 2, 3]:
	count(x)
	if x == 3:
		count(x + 1)
Disabled highlighting 
<div id="contents">
  <p>Hello, World!
</div>