Java SE (Java Platform, Standard Edition)

Is anyone familiar with linktivity web interactive?
http://www.linktivity.com

I was wondering if there was a product like this available for linux

Basically (TO THE BEST OF MY UNDERSTANDING), It works on a web server and users can browse to that web server and start a java application which shares their desktop interface.

Remotely (at a third location) a technician can log into the same server and view the user's desktop and interact just like it was a vnc connection.

The advantage I see is that the user never has to "install" anything, start any services, or open any ports on their firewall/router to share their desktop. All they have to do is browse to the website and load the java applet and they are ready. Also it is nice that the technician can be at a third location and not on the web server or at the site (via vpn connection or some other method).

any advice would be appreciated.