Ubuntu can control an OS X machine remotely, using the Terminal Server Client program that comes with Gnome.

Setting up the Mac to be Accessed Remotely

On the Mac:

• Open System Preferences (it's in the Apple menu).
• Open the "Sharing" panel.

• Check the box Apple Remote Desktop.

• Click Access Privileges

• Check the box VNC viewers may control screen with password, and enter a password.

• Click OK.

Setting up Ubuntu to Access the Mac

On Ubuntu:

Ubuntu requires the following proceedure to be done once to ensure the correct 'Tight VNC' protocol is used to access the Mac, rather than regular VNC, which won't work (if VNC is used, the connection will fail with a 'Unknown message type 255 from VNC server' response).

• Click System > Administration > Synaptic Package Manager

• Install the xtightvncviewer package.

• Click Applications > Accessories > Terminal

• In the terminal type:

update-alternatives --set vncviewer /usr/bin/xtightvncviewer

Accessing the Mac From Ubuntu

• Click Applications > Internet > Terminal Server Client

• For Computer, type in the host name of the computer.

For Protocol, choose VNC Then click 'Connect'

A password dialog will pop up. Type your password and hit enter.

Your Mac's desktop should appear on your screen.

Discussion

In Mac OS X 10.3.9, the Access Privileges sheet doesn't have a "VNC viewers may control screen with password" checkbox, or any mention of VNC. -- MatthewPaulThomas

UPDATED Links for 10.3.9 : Apple Remote Desktop 3.2 ( Note: the links below no longer work but I'll leave them for historical sake ) -- -- imbrandon 2008-02-04 07:48:02

Mac OS X 10.3.x (Panther) ships with an old version of Apple Remote Desktop Client that does not interoperate with third-party VNC viewers. You can correct this by downloading and installing Apple Remote Desktop Client 2.2 to match what's bundled with Mac OS X 10.4.x (Tiger). Alternatively, you can upgrade 10.3.9 or 10.4.x to have Apple Remote Desktop Client 3.1, which Apple says "is recommended for all users." -- EricPScott

By default Apple Screen Sharing uses a proprietary security type and so clients such as vinagre, xvnc4viewer will receive error messages such as "incompatible version" or "no matching security types." Fix using the steps in the first section or via the command line, such as via ssh, replacing with your desired VNC password as appropriate:

{{{/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart

• -configure -clientopts -setvnclegacy -vnclegacy yes -setvncpw -vncpw ***password*** -restart -agent}}}

Working Clients

• gnome-rdp
• xtightvncviewer

• xvnc4viewer: only with -FullColour, but very slow:

xvnc4viewer -FullColour macserver

Broken Clients

• tsclient (Terminal Server Client)
• vinagre (Remote Desktop Viewer)

-- StevenMcCoy