VMware only provides a Virtual Infrastructure Client (also known as VIC or viclient) for the Windows platform. VMware have stated (during VMworld) that a linux version of this client is in the works, but it's still not known when it will be available, but probably not before the next major esx product version.

It is possible (with a few limitations) to run the native windows client under other OSes using WINE by following this howto: http://www.virtualinsanity.com/index.php/2009/02/02/vmware-infrastructure-client-on-ubuntu-an-update/

There is also an open source client called Kodiak in the works. It's written in Adobe ActionScript and will work for Linux, OSX and Windows.

If all you need is to access the consoles of the virtual machines it's also possible to use vmware-vmrc from the VMware Server 2.0 web interface (plugin that is installed through the web interface that can be used standalone) or to use iMKS - The Remote Console Appliance.

Another possibility is to use VMware Player as a remote console with the command: vmplayer -h ip.address.of.your.host