For anyone curious: The third-party tool was Karelia's Watson, which was a tool that let you search websites, with the ability to add support for new websites through plug-ins. In OS X 10.2, Apple added the same functionality to their "find file" tool Sherlock (and IMO made the program worse than either Sherlock or Watson were on their own).

They have also done this with Spotlight, taking over functionality of app launchers / utilities like Quicksilver and Alfred.

Funnily enough, Apple also got into competition with Karelia's next product, Sandvox, when they released iWeb. That didn't seem to kill Sandvox the way Sherlock did Watson, though.

To be fair... iWeb was pretty bad. I tried to use it. Nope.

Oh, I thought it was earlier than that. I also couldn't remember if Sherlock was the Apple tool or the 3rd party one.

I didn't come back to the Mac until a hair before 10.4, so I don't have first hand experience.