How does the DropBox Mac client work?

Question

I\'ve been looking at the DropBox Mac client and I\'m currently researching implementing a similar interface for a different service.

How exactly do they interface wit

Answer 1

Dropbox is likely using FSEvents to watch for changes to the file system. It's a great API and can even bundle up changes that happened while your app was not running. It's the same API that Spotlight uses. The menubar app likely does the actual observing itself (since restarting it can fix uploads being hung, for instance).

There's no way they're using MacFUSE, as that would require installing the MacFUSE kernel extension to make Dropbox work, and since I definitely didn't install it, I highly doubt they're using it.