ITS is a timesharing system created at MIT's Artificial Intelligence Laboratory in 1967 for their PDP-6 computer. It was soon moved to the newer PDP-10; for most of its life ITS ran on four of those machines. ITS is known for it's lack of security (no passwords, no file permissions), using a debugger as the login shell, and pioneering many famous programs.

The SDF ITS is at https://hactrn.org/ and is running on a KA10 emulator with an attached PDP-11 for serving Knight TV raster graphics terminals.

Some basic tutorials:

• HACTRN survival guide
• Adding a new ITS user

More information can be found by running INFO, and on GitHub.

Suggested topics to explore:

• Zork and Advent, classic text adventure games.
• Emacs, the first version.
• Maclisp and Scheme, major Lisp dialects.
• Macsyma, symbolic math.
• Logo, programming for kids.
• C, pre-K&R version.
• Muddle, the Dynamic Modeling programming language.
• Maze, the 3D first person shooter (needs an Imlac emulator).