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<< "Hello, World!" MSGBOX >>
<< "Hello, World!" MSGBOX >>

=== [[SWT]] ===
import org.eclipse.swt.widgets.*;

public class Main {
public static void main (String [] args) {
Display display = new Display ();
Shell shell = new Shell(display);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
}


=== [[Visual Basic]] incl [[Visual Basic for Applications|VBA]] ===
=== [[Visual Basic]] incl [[Visual Basic for Applications|VBA]] ===

Revision as of 21:19, 13 August 2004

A "hello world" program is a computer program that simply prints out "Hello, world!" on a display device. It is used in many introductory tutorials for teaching a programming language and many students use it as their first programming experience in a language.

Such a program is typically one of the simpler programs possible in a computer language. Some are surprisingly complex, especially in some graphical user interface (GUI) contexts. Some others are surprisingly simple, especially those which rely heavily on a particular command line interpreter ("shell") to perform the actual output. In many embedded systems, the text may be sent to a one or two-line LCD display (and in yet other systems, a simple LED being turned on may substitute for "Hello world!").

A "hello world" program can be a useful sanity test to make sure that a language's compiler, development environment, and run-time environment are correctly installed. Configuring a complete programming toolchain from scratch to the point where even trivial programs can be compiled and run may involve substantial amounts of work. For this reason, a simple program is used first when testing a new tool chain.

While small test programs existed since the development of programmable computers, the tradition of using the phrase "Hello, world!" as the test message was influenced by an example program in the book The C Programming Language, by Brian Kernighan and Dennis Ritchie. The example program from that book prints "hello, world" (i.e., no capital letters, no exclamation sign; those have entered the tradition later). However, the first known instance of the usage of "Hello world!" is in A Tutorial Introduction to the Language B, by Brian Kernighan. [1]

A collection of "hello world" programs written in various computer languages can serve as a very simple "Rosetta Stone" to assist in learning and comparing the languages. Keep in mind, however, that unless assembly language or similar very low-level (hardware-near) languages are involved, not much "computing" in the way of actual calculation, is usually exhibited.

Here are some examples in different languages:

Text user interface (TUI) (aka console, line-oriented)


   WRITE "Hello World"
   with Ada.Text_Io; use Ada.Text_Io;
   procedure Hello is
   begin
      Put_Line ("Hello, world!");
   end Hello;
   PROC main()
      WriteF('Hello, World!')
   ENDPROC
   'Hello World'

Accumulator-only architecture: DEC PDP-8, PAL-III assembler

See the example section of the PDP-8 article.

First successful µP/OS combinations: Intel 8080/Zilog Z80, CP/M, RMAC assembler

   bdos    equ    0005H    ; BDOS entry point
   start:  mvi    c,9      ; BDOS function: output string
           lxi    d,msg$   ; address of msg
           call   bdos
           ret             ; return to CCP
 
   msg$:   db    'Hello, world!$'
   end     start

Accumulator + index register machine: MOS Technology 6502, CBM KERNAL, ca65 assembler

   MSG:   .ASCIIZ "Hello, world!"
           LDX    #0
           LDA    MSG,X    ; load initial char
   @LP:    JSR    $FFD2    ; chrout
           INX
           LDA    MSG,X
           BNE    @LP
           RTS

Accumulator/Index microcoded machine: Data General Nova, RDOS

See the example section of the Nova article.

Expanded accumulator machine: Intel x86, MS-DOS, TASM

   MODEL   SMALL
   IDEAL
   STACK   100H
 
   DATASEG
           MSG DB 'Hello, world!$'
 
   CODESEG
           MOV AX, @data
           MOV DS, AX
           MOV DX, OFFSET MSG
           MOV AH, 09H      ; DOS: output ASCII$ string
           INT 21H
           MOV AX, 4C00H
           INT 21H
   END

General-purpose fictional computer: MIX, MIXAL

   TERM    EQU    19          console device no. (19 = typewriter)
           ORIG   1000        start address
   START   OUT    MSG(TERM)   output data at address MSG
           HLT                halt execution
   MSG     ALF    "HELLO"
           ALF    " WORL"
           ALF    "D    "
           END    START       end of program

General-purpose-register CISC: DEC PDP-11, RT-11, MACRO-11

  .MCALL  .REGDEF,.TTYOUT,.EXIT
          .REGDEF
 
   HELLO:  MOV    #MSG,R1
           MOVB   (R1),R0
   LOOP:  .TTYOUT
           MOVB  +(R1),R0
           BNE    LOOP
          .EXIT
 
   MSG:   .ASCIZ  /HELLO, WORLD!/
          .END    HELLO

CISC on advanced multiprocessing OS: DEC VAX, VMS, MACRO-32

           .title    hello
 
           .psect    data, wrt, noexe
 
   chan:   .blkw     1
   iosb:   .blkq     1
   term:   .ascid    "SYS$OUTPUT"
   msg:    .ascii    "Hello, world!"
   len =   . - msg
 
           .psect    code, nowrt, exe
 
           .entry    hello, ^m<>
 
           ; Establish a channel for terminal I/O
           $assign_s devnam=term, -
                     chan=chan
           blbc      r0, end
 
           ; Queue the I/O request
           $qiow_s   chan=chan, -
                     func=#io$_writevblk, -
                     iosb=iosb, -
                     p1=msg, -
                     p2=#len
 
           ; Check the status and the IOSB status
           blbc      r0, end
           movzwl    iosb, r0
 
           ; Return to operating system
   end:    ret
 
          .end       hello

RISC processor: ARM, RISC OS, BBC BASIC's in-line assembler

  .program         
           ADR R0,message
           SWI "OS_Write0"
           SWI "OS_Exit"
  .message         
           DCS "Hello, world!"
           DCB 0
           ALIGN

or the even smaller version (from qUE);

           SWI"OS_WriteS":EQUS"Hello, world!":EQUB0:ALIGN:MOVPC,R14
   BEGIN { print "Hello, world!" }

MS BASIC (traditional, unstructured)

   10 PRINT "Hello, world!"
   20 END

On TI-80-TI-83 calculators.

   :Disp "Hello, world!"

On TI-89/TI-92 calculators.

   :HelloWorld()
   :Prgm
   :Disp "Hello, world!"
   :EndPrgm
   sub main
       print "Hello, World"
   end sub

Structured BASIC

   print "Hello, world!"
   end
   GET "LIBHDR"
 
   LET START () BE
   $(
       WRITES ("Hello, world!*N")
   $)


   %TITLE 'HELLO_WORLD'
   MODULE HELLO_WORLD (IDENT='V1.0', MAIN=HELLO_WORLD,
           ADDRESSING_MODE (EXTERNAL=GENERAL)) =
   BEGIN
 
       LIBRARY 'SYS$LIBRARY:STARLET';
 
       EXTERNAL ROUTINE
          LIB$PUT_OUTPUT;
 
   GLOBAL ROUTINE HELLO_WORLD =
   BEGIN
 
       LIB$PUT_OUTPUT(%ASCID %STRING('Hello World!'))
   END;
 
   END
   ELUDOM
    #include <stdio.h>

    int main()
    {
        printf("Hello, world!\n");
        return 0;
    }
    using System;

    class HelloWorldApp {
        public static void Main() {
            Console.WriteLine("Hello, world!");
        }
    }
    #include <iostream>

    int main()
    {
        std::cout << "Hello, world!" << std::endl;
    }
   .method public static void Main() cil managed
   {
        .entrypoint
        .maxstack 8
        ldstr "Hello world."
        call void [mscorlib]System.Console::WriteLine(string)
        ret
   }
   module hello
 
   Start :: String
   Start = "Hello, world"
   PROC 0
   WRITE Hello, World!
   IDENTIFICATION DIVISION.
   PROGRAM-ID.     HELLO-WORLD.
 
   ENVIRONMENT DIVISION.
 
   DATA DIVISION.
 
   PROCEDURE DIVISION.
   DISPLAY "Hello, world!".
   STOP RUN.
   (format t "Hello world!~%")
   int main() {
       printf("Hello, world!\n");
       return 0;
   }

DCL batch

   $ write sys$output "Hello, world!"


Ed and Ex (Ed extended)

   a
   hello world!
   .
   p

or like so:

   echo -e 'a\nhello world!\n.\np'|ed
   echo -e 'a\nhello world!\n.\np'|ex
   class HELLO_WORLD
 
   creation
       make
   feature
       make is
       local
               io:BASIC_IO
       do
               !!io
               io.put_string("%N Hello, world!")
       end -- make
   end -- class HELLO_WORLD
       -module(hello).
       -export([hello_world/0]).
 
       hello_world() -> io:fwrite("Hello, world!\n").
   puts(1, "Hello, world!")
   type data =
       { first: string;
         second: string; }
 
       let myData =
           { first="Hello";
             second="world"; }
 
       let _ =
           print_string myData.first;
           print_string " ";
           print_string myData.second;
           print_newline()
   begin TOOL HelloWorld;
 
   includes Framework;
   HAS PROPERTY IsLibrary = FALSE;
 
   forward  Hello;
 
   -- START CLASS DEFINITIONS
 
   class Hello inherits from Framework.Object
 
   has public  method Init;
 
   has property
       shared=(allow=off, override=on);
       transactional=(allow=off, override=on);
       monitored=(allow=off, override=on);
       distributed=(allow=off, override=on);
 
   end class;
   -- END CLASS DEFINITIONS
 
   -- START METHOD DEFINITIONS
 
   ------------------------------------------------------------
   method Hello.Init
   begin
   super.Init();
 
   task.Part.LogMgr.PutLine('HelloWorld!');
   end method;
   -- END METHOD DEFINITIONS
   HAS PROPERTY
       CompatibilityLevel = 0;
       ProjectType = APPLICATION;
       Restricted = FALSE;
       MultiThreaded = TRUE;
       Internal = FALSE;
       LibraryName = 'hellowor';
       StartingMethod = (class = Hello, method = Init);
 
   end HelloWorld;
   ." Hello, world!" CR
      PROGRAM HELLO
      WRITE(*,10)
   10 FORMAT('Hello, world!')
      STOP
      END
   println["Hello, world!"]

See also GUI section.

   PUBLIC SUB Main()
     Print "Hello, world!"
   END

In the draw event of some object:

   draw_text(x,y,"Hello World");
   module HelloWorld (main) where
 
   main = putStr "Hello World\n"
 program HelloWorld;
 functions {
   _main() {
     String("Hello, world!") |> GetStdOut();
   }
 }
 end

(Handheld Hewlett-Packard RPN-based alphanumeric engineering calculators.)

 
   01 LBLTHELLO
   02 THELLO, WORLD
   03 PROMPT

HP-41 output


   ON ENTER {
       "Hello, " "World!" & SAY
   }
   "Hello world!" print

or

   write("Hello world!\n")

See also GUI section.

   public class Hello {
       public static void main(String[] args) {
           System.out.println("Hello, world!");
       }
   }

(disassembler output of javap -c Hello.class)

   public class Hello extends java.lang.Object {
       public Hello();
       public static void main(java.lang.String[]);
   }

   Method Hello()
      0 aload_0
      1 invokespecial #1 <Method java.lang.Object()>
      4 return

   Method void main(java.lang.String[])
      0 getstatic #2 <Field java.io.PrintStream out>
      3 ldc #3 <String "Hello, world!">
      5 invokevirtual #4 <Method void println(java.lang.String)>
      8 return
   WriteLine "Hello, world!"
   print [hello  world!]

or

   pr [Hello World!]

In mswlogo only

   messagebox [Hi] [Hello World]
   print "Hello, world!"
   W "Hello, world!"
   MODULE Hello;
 
   FROM Terminal2 IMPORT WriteLn; WriteString;
 
   BEGIN
      WriteString("Hello, world!");
      WriteLn;
   END Hello;

MS-DOS batch

(with the standard command.com interpreter. The @ symbol is optional and prevents the system from repeating the command before executing it. The @ symbol must be omitted on versions of MS-DOS prior to 5.0.)

   @echo Hello, world!
   : main
     me @ "Hello, world!" notify
   ;
   
  #import <Foundation/Foundation.h>
   int main (int argc, const char * argv[]) {
      NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
      NSLog(@"Hello, World!");
      [pool release];
      return 0;
  }
   let _ =
      print_endline "Hello world!";;

See also GUI section.

   PROC hello:
     PRINT "Hello, World"
   ENDP
   (object-class request
            ^action)
 
   (startup
      (strategy MEA)
      (make request ^action hello)
   )
 
 
   (rule hello
      (request ^action hello)
      -->
        (write |Hello World!| (crlf))
   )
   program Hello;
   begin
       writeln('Hello, world!');
   end.
   print "Hello, world!\n";
<?php echo "Hello, world!"; ?>
   int main() {
       write("Hello, world!\n");
       return 0;
   }
   Test: procedure options(main);
      declare My_String char(20) varying initialize('Hello, world!');
      put skip list(My_String);
   end Test;
   'Hello world' =>
 #include "colors.inc"
 camera {
   location <3, 1, -10>
   look_at <3,0,0>
 }
 light_source { <500,500,-1000> White }
 text {
   ttf "timrom.ttf" "Hello world!" 1, 0
   pigment { White }
 }
   write('Hello world'),nl.
   print "Hello, world!"

or:

   import sys
   sys.stdout.write("Hello, World\n")
  say "Hello, world!"

or:

  say 'Hello, world!'

See also GUI section.

(On Hewlett-Packard HP-28, HP-48 and HP-49 series graphing calculators.)

   <<
     CLLCD
     "Hello, World!" 1 DISP
     0 WAIT
     DROP
   >>


See also GUI section.

   puts "Hello, world!"
   class HELLO_WORLD is
     main is 
      #OUT+"Hello World\n"; 
     end; 
   end;
   object HelloWorld with Application {
     Console.println("Hello, world!");
   }
   (display "Hello, world!")
   (newline)

(note: requires at least one line of input)

   sed -ne '1s/.*/Hello, world!/p'
   'Hello, World!' print.
   Transcript show: 'Hello, world!'
   print "Hello, world!\n";
       OUTPUT = "Hello, world!"
   END
   create table MESSAGE (TEXT char(15));
   insert into MESSAGE (TEXT) values ('Hello, world!');
   select TEXT from MESSAGE;
   drop table MESSAGE;

Or (e.g. Oracle dialect)

   select 'Hello, world' from dual;

Or (e.g. MySQL dialect)

   select 'Hello, world';

Or, more simply

   print 'Hello, World.'

Or (for KB-SQL dialect)

   select Null from DATA_DICTIONARY.SQL_QUERY

   FOOTER or HEADER or DETAIL or FINAL event
   write "Hello, World!"
   RACINE: HELLO_WORLD.
 
   NOTIONS:
   HELLO_WORLD : ecrire("Hello, world!").
   #OUTPUT Hello, world!
   puts "Hello, world!"
   put "Hello, world!"
   Declare @Output varchar(16)
   Set @Output='Hello, world!'
   Select @Output
 
     or, simpler variations:
 
   Select 'Hello, world!'
   Print 'Hello, world!'
   echo 'Hello, world!'

Graphical user interfaces (GUIs)


ActionScript (Macromedia flash mx)

   trace ("hello, world")
   display dialog "Hello, world!"

Or to have the OS synthesize it and literally say "hello world!"

  say "Hello world!" -- comma left out because that would cause the synthesizer to pause and sound silly

Cocoa or GNUStep (In Objective C)

  #import <Cocoa/Cocoa.h>
  @interface hello : NSObject {
  }
  @end


  @implementation hello
  -(void)awakeFromNib
  {	
       NSBeep(); // we don't need this but it's conventional to beep when you show an alert
       NSRunAlertPanel(@"Message from your Computer", @"Hello, world!", @"Hi!", nil, nil);
  }
  @end
   ShowMessage("Hello, world!");

See also TUI section.

   PUBLIC SUB Main()
     Message.Info("Hello, world!")
   END

File:Gambashelloworld.png

GTK toolkit (in C++)

   #include <iostream>
   #include <gtkmm/main.h>
   #include <gtkmm/button.h>
   #include <gtkmm/window.h>
   using namespace std;
 
   class HelloWorld : public Gtk::Window {
   public:
     HelloWorld();
     virtual ~HelloWorld();
   protected:
     Gtk::Button m_button;
     virtual void on_button_clicked();
   };
 
   HelloWorld::HelloWorld()
   : m_button("Hello, world!") {
       set_border_width(10);
       m_button.signal_clicked().connect(SigC::slot(*this,
                                         &HelloWorld::on_button_clicked));
       add(m_button);
       m_button.show();
   }
 
   HelloWorld::~HelloWorld() {}
 
   void HelloWorld::on_button_clicked() {
       cout << "Hello, world!" << endl;
   }
 
   int main (int argc, char *argv[]) {
       Gtk::Main kit(argc, argv);
       HelloWorld helloworld;
       Gtk::Main::run(helloworld);
       return 0;
   }

GTK 2.x (in Euphoria)

   include gtk2/wrapper.e
 
   Info(NULL,"Hello","Hello World!")

File:EuphoriaHelloWorld.png

See also TUI section.

   import javax.swing.JOptionPane;
 
   public class Hello {
       public static void main(String[] args) {
           JOptionPane.showMessageDialog(null, "Hello, world!");
           System.exit(0);
       }
   }
Java applets work in conjunction with HTML files.
   <HTML>
   <HEAD>
   <TITLE>Hello World</TITLE>
   </HEAD>
   <BODY>
 
   HelloWorld Program says:
 
   <APPLET CODE="HelloWorld.class" WIDTH=600 HEIGHT=100>
   </APPLET>
 
   </BODY>
   </HTML>
 
   import java.applet.*;
   import java.awt.*;
 
   public class HelloWorld extends Applet {
     public void paint(Graphics g) {
       g.drawString("Hello, world!", 100, 50);
     }
   }

JavaScript (aka ECMAScript) and JScript

JavaScript is a client-side scripting language used in HTML files. The following code can be placed in any HTML file.
    <script type="text/javascript"><!--
    function helloWorld()
    {
        alert("Hello, world!");
    }
    //--></script>
 
    <a href="#" onclick="helloWorld()">Hello World Example</a>
An easier method uses JavaScript implicitly, calling the reserved alert function. Cut and paste the following line inside the <BODY> .... </BODY> HTML tags.
    <a href="#" onclick="alert('Hello, world!')">Hello World Example</a>
An even easier method involves using popular browsers' support for the virtual 'javascript' protocol to execute JavaScript code. Enter the following as an Internet address (usually by pasting into the address box):
    javascript:alert('Hello, world!')

File:Js-hello world.png

See also TUI section.

(On Psion Series 3 and later compatible PDAs.)

   PROC guihello:
     ALERT("Hello, world!","","Exit")
   ENDP

Qt toolkit (in C++)

   #include <qapplication.h>
   #include <qpushbutton.h>
   #include <qwidget.h>
   #include <iostream>
 
   class HelloWorld : public QWidget
   {
       Q_OBJECT
 
   public:
       HelloWorld();
       virtual ~HelloWorld();
   public slots:
       void handleButtonClicked();
       QPushButton *mPushButton;
   };
 
   HelloWorld::HelloWorld() :
       QWidget(),
       mPushButton(new QPushButton("Hello, World!", this))
   {
       connect(mPushButton, SIGNAL(clicked()), this, SLOT(handleButtonClicked()));
   }
 
   HelloWorld::~HelloWorld() {}
 
   void HelloWorld::handleButtonClicked()
   {
       std::cout << "Hello, World!" << std::endl;
   }
 
   int main(int argc, char *argv[])
   {
       QApplication app(argc, argv);
       HelloWorld helloWorld;
       app.setMainWidget(&helloWorld);
       helloWorld.show();
       return app.exec();
   }
   MsgBox "Hello, world!"

See also TUI section.

(On Hewlett-Packard HP-48G and HP-49G series calculators.)


   << "Hello, World!" MSGBOX >>

import org.eclipse.swt.widgets.*;

public class Main {

       public static void main (String [] args) {

Display display = new Display (); Shell shell = new Shell(display); shell.open (); while (!shell.isDisposed ()) { if (!display.readAndDispatch ()) display.sleep (); } display.dispose ();

       }

}

   MsgBox "Hello, world!"
   #include <windows.h>
 
   LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
 
   char szClassName[] = "MainWnd";
   HINSTANCE hInstance;
 
   int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
   {
     HWND hwnd;
     MSG msg;
     WNDCLASSEX wincl;
 
     hInstance = hInst;
  
     wincl.cbSize = sizeof(WNDCLASSEX);
     wincl.cbClsExtra = 0;
     wincl.cbWndExtra = 0;
     wincl.style = 0;
     wincl.hInstance = hInstance;
     wincl.lpszClassName = szClassName;
     wincl.lpszMenuName = NULL; //No menu
     wincl.lpfnWndProc = WindowProcedure;
     wincl.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); //Color of the window
     wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION); //EXE icon
     wincl.hIconSm = LoadIcon(NULL, IDI_APPLICATION); //Small program icon
     wincl.hCursor = LoadCursor(NULL, IDC_ARROW); //Cursor
  
     if (!RegisterClassEx(&wincl))
           return 0;
 
     hwnd = CreateWindowEx(0, //No extended window styles
           szClassName, //Class name
           "", //Window caption
           WS_OVERLAPPEDWINDOW & ~WS_MAXIMIZEBOX,
           CW_USEDEFAULT, CW_USEDEFAULT, //Let Windows decide the left and top positions of the window
           120, 50, //Width and height of the window,
           NULL, NULL, hInstance, NULL);
 
     //Make the window visible on the screen
     ShowWindow(hwnd, nCmdShow);
  
     //Run the message loop
     while (GetMessage(&msg, NULL, 0, 0))
     {
           TranslateMessage(&msg);
           DispatchMessage(&msg);
     }
     return msg.wParam;
   }
 
   LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
   {
     PAINTSTRUCT ps;
     HDC hdc;
     switch (message)
     {
     case WM_PAINT:
           hdc = BeginPaint(hwnd, &ps);
           TextOut(hdc, 15, 3, "Hello, world!", 13);
           EndPaint(hwnd, &ps);
           break;
     case WM_DESTROY:
           PostQuitMessage(0);
           break;
     default:
           return DefWindowProc(hwnd, message, wParam, lParam);
     }
     return 0;
   }

  Or much more easy :

   #include <windows.h>
   int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
   {
       MessageBox(NULL, "Hello World", "", MB_OK);
       return 0;
   }

See also TUI section.

require 'wxruby'

class HelloWorldApp < Wx::App
 def on_init
  ourFrame = Wx::Frame.new(nil, -1, "Hello, world!").show
  ourDialogBox = Wx::MessageDialog.new(ourFrame, "Hello, world!", "Information:", Wx::OK|Wx::ICON_INFORMATION).show_modal
 end
end

HelloWorldApp.new.main_loop
   <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
   <box align="center">
   <label value="Hello, world!" />
   </box>
   </window>

Document Formats


The following sequence of characters, expressed in hexadecimal notation (with carriage return and newline characters at end of sequence):

    48 65 6C 6C 6F 2C 20 77 6F 72 6C 64 21 0D 0A

HTML 4.01 Strict

(Using UTF-8 character set.)

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
  <head>
    <title>Hello, world!</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>

XHTML 1.1

(Using UTF-8 character set.)

Please note that this document must also be sent with the appropriate HTTP Header, most preferably "application/xhtml+xml", but it MAY also be sent as "application/xml" or "text/xml"; however it MUST NOT be sent as "text/html"; see XHTML Media Types for further info.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  <head>
    <title>Hello, world!</title>
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>


   {\rtf1\ansi\deff0
   {\fonttbl {\f0 Courier New;}}
   \f0\fs20 Hello, world!
   }
   /Courier findfont 24 scalefont setfont
   100 100 moveto
   (Hello world!) show
   showpage
In executing the interpreter, one can simply write
(Hello world!) stack
   Hello world
   \bye

See also