What (typed as :what in the HACTRN prompt) was a small information utility available in the Incompatible Timesharing System. It could provide information about incoming email, bus schedule on the MIT campus, executable source files or answer the user in a humorous manner.
:what was written in the MIDAS assembly language. It can still be used on some of the ITS instances maintained across the web. The last traceable edit of the source code was by Ken L. Harrenstien on 16 May 1988.
Without arguments :what would print information about inbox status:
*:what
You don't seem to have any recent messages.
:KILL E$J
*
With the argument bus it would print out information about the next few buses leaving from the MIT campus:
*:what bus
It is now 12:50
Bus 83 leaves Central Sq 13:10, 13:30, 13:45, 14:00, ...
Bus 83 leaves Ringworld/Alewife 13:00, 13:20, 13:40, 13:55, ...
:KILL E$J
*
Asked about source for NAME, :what responded with paths to source files corresponding to NAME:
*:what source for what
UP:SYSENG;
0 WHAT 201 3 +487 11/30/1987 17:33:23 (5/2/2015) KLH
0 WHAT 204 3 +493 5/16/1988 19:13:03 (5/4/2015) KLH
*
Not knowing the answer, it would often resort to humor:
*:what is life
You tell me.
:KILL E$J
*
Finally, :what displayed some amount of introspection:
*:what is this
It's an all purpose utility program, dummy!
:KILL E$J
*:what are you
I am an omniscient utility program, idiot!
:KILL E$J
*
