Access to files and folders with a Mac

Hi!

I'am looking for a way to access the files and folders located in a team site with a Mac running Mac OS X.

I'd like to access those not from a web page in a browser, but in a folder on the Finder: the same way we can access those in the Windows Explorer on a PC running Windows.

Do I have to buy a third party tool (Colligo briefcase seems nice...)?

Thanks

Nicolas