Mac OS X only: If you run any kind of server on your Mac with Leopard, you'll dig its revamped Sharing and Network System Preferences panels, which offer new features in a reorganised interface. One huge drawback in Tiger is that unless you install extra software, you can turn on Windows Sharing for your home folder only. No more. Using Leopard, share any folder on your Mac via FTP, Samba, or AFP (Apple Filing Protocol), from a single, easy interface. Take a closer look after the jump. In System Preferences' Sharing pane all the possible items to share on your Mac are listed—printers, files, internet, Bluetooth, and Screen (more on that later.)
Select "File Sharing" to share any folder on your Mac with custom permissions based on user. When you hit the Options button, set the sharing protocol (AFP, Samba Windows Sharing, or FTP.)
One of my Macs hosts media that streams to my Xbox Media Center using Samba. In Tiger, to share out the external drive that contains the files to the XBMC, I had to install the extra SharePoints preference pane, but in Leopard, that's no longer necessary.
Further, if you wanted to remote control your Mac, you had to install a VNC server and client or Apple Remote Desktop. Now dead-simple VNC is baked into Leopard, and can control another Mac on your home network using the Screen Sharing client application. Check off "Screen Sharing" in the Sharing Preference pane to turn it on the server.
Printer sharing has also been relocated from Printers & Fax to the Sharing pane, which makes a lot more sense. It's also a two-click process to share your internet connection to another computer, like in an wired-only hotel, for instance.
Similarly, the Network System Preference Pane has been reorganised to display every type of possible connection in a much more intuitive interface.
The fact that iChat Screen Sharing and Document Theater is one of its marquee features demonstrates that Apple intended Leopard to be a much more social operating system. It's nice to see that the file serving options under the hood in System Preferences are just as easy to use.