codingdave
Call me crazy, but have you tried asking Yahoo?

Worst that can happen is they quickly say no, but you never know. Something that old and irrelevant to their current operations, maybe they would open source the old code. Or maybe they deleted it years ago. But you won't know unless you ask.

I am curious what you would want with it? Geocities was coded so early in the history of the web that odds are that code isn't anything that you'd run again today.