Telnetting to each of the indicated ports connects you to a text-adventure game. They're all the same game, except that they are engineered to "crash" at different points, and in different ways. From the error message produced, you can deduce what language the game was supposedly written in:
3001: Eiffel
3002: Java
3003: Perl
3004: Python
3005: Rexx
3006: Ruby
3007: Scheme
(Conveniently in alphabetical order, which can help deduce the language, though it is not really necessary. Yes, that really has to be Scheme and not Lisp: Lisp doesn't define #f.)
Now, to get the answer out, think about standard troubleshooting procedure: what were you doing right before it crashed? In each case, the crash occurs immediately after the user enters a number. Take that number as an index into the name of the programming language, and order chronologically by the point in the game at which the crash occurs. This spells VMLINUX, which is the answer.
For the curious, the game was actually written in C++, and fakes all the crashes. Crash messages were lovingly crafted to be realistic by Reid Barton. The title is a reference to an amusing LaTeX error message.
And here's a list of moves which will get you through the entire game (two moves longer than the shortest possible because I prefer to bribe the security guard with donuts):
2 1 L 1 3 2 1 1 1 1 1 1 1 2 5 1 3 3 4 1 1 6 6 1 2 R 1 1 2 1 2 R 1 1 2 1 2 R 1 1 3 1 2 R 1 1 2 1 2 2 L 1 6 2 L 1 5 2 L 1 4 2 L 1 3 2 R 6 2 R 1 3 2 R 1 3 2 R 1 3 2 L 4 2 L 1 4 2 L 1 3 2 R 3 2 R 1 3 2 2 L 1 3 2 R 3 2 2 2 1 1 3 1 1 1 2 1 1 1 5 6 1 2 2 2 2 1 3 1 L R 2 1 3 3
2006 MIT Mystery Hunt