Within MacOS X 1.5 Leopard there is a built-in VNC compatible screen sharing. To enable vncserver, goto System Preferences -> Sharing.
To connect to any VNC session with vncviewer (it’s called ‘Screen Sharing App’), left click on Finder button, ‘Connect to Server’ and type in the complete URI like ‘vnc://host.name.tld:5902’ for connecting to desktop :2. There is no need to specify the port if you connect to desktop :0.
So there is no need for any additional client application like ‘Chicken of the VNC’.