oldest software in use?

[Jeremy C. Reed]

On Fri, 1 Dec 2006, Jerry Davis wrote:

> Well, I worked for DEC all through the 80's.
> I still like to use the game of Adventure.
> That was written by Don Woods in the early to mid 70's.

The version on my NetBSD system was a rewrite (from Fortan to C) done in 
1991 I think. It has recent updates this year, including two bug fixes 
found by Coverity.

Do you still use the old software? 

I am mostly curious about old software that has not been updated too.