Orlando's bus system, Lynx, has multiple routes that connect the World to Orlando. And then there's the I-Ride, a trolley that runs up and down International Drive.
Some people who visit the World from Not the US find these things out and occasionally take advantage of them. I'm still trying to figure out if any of the guidebooks I've looked at so much as mentioned them. Hmmmm...
If you're wondering, no, I'm not trying to save money. This is an ongoing effort to get to places without using kid car seats.
(edited to remove excessive use of the word "apparently")