# ITS Attractions

**Maclisp** — historical Lisp for ITS and Multics, and the base
for a family of dialects that consolidated as the Common Lisp standard.
It was used to bootstrap **Scheme**.

**SHRDLU** — infamous natural language input and block stacking
robot simulation, written in Maclisp.

**Lisp machines** — were bootstrapped from ITS and Maclisp.

**C compiler** — written by Alan Snyder; possibly the first
created outside Bell Labs.

**Macsyma** — symbolic manipulation program that was written in
Maclisp and made available to researchers on the Arpanet.  Macsyma was
so important a dedicated PDP-10 was purchased for it, not just once,
but twice.

**Emacs** — was developed on ITS as a set of **TECO** macros.

**The Magic Switch** — a piece of hacker lore chronicled in Guy
Steele's book *Hacker's Dictionary*.  The book comes from the
**JARGON** file.

**Logo** — educational programming language began at BBN but
greatly enhanced at MIT.  ITS hosts many versions for the PDP-10,
PDP-11, Apple II, etc.  A **Small ITS** timesharing system was written
to run Logo on a PDP-11/45.  Marvin Minsky designed the **2500**, a
dual text and vector display minicomputer for running Logo.

**CLU** — a programming language by Barbara Liskov that
introduced abstract data types way ahead of its times.  The CLU group
developed the first version of the X Window System.

**Zork** — was written in **MDL**/**Muddle**, the major
programming language on the Dynamic Modeling PDP-10.  Zork was
inspired by (**Colossal Cave**) **Advent**ure, which is also available
on ITS.  Together, the two games were instrumental in kicking off text
adventure games and interactive fiction.

**Maze** — 3D game, and possibly the first first-person shooter.

**MacHack VI** — Greenblatt's chess program was the first
computer program to play chess in human tournament competitions and be
granted a chess rating.

**Spacewar** — one of the first video games.  First developed on
a PDP-1 at MIT.  ITS has a much updated PDP-6 version, and consoles
made by **HAKMEM** author Mike Beeler.