Our instructions for visual access use a No Machine product called 3.5 Client. Unfortunately, this is no longer available.
Nx 4.0 Player DOES WORK with our service although it can take 4 or 5 attempts typically to get a connection and setup is more complex. I am working on a new set of instructions of use with it.
Also, on Windows and Linux, OpenNX and X2Go also work with our system although X2Go sometimes doesn’t play nice with other applicaitons. On McIntosh systems, these products seem to have key mapping issues.
An alternative to No Machine (NX) 4.0 Player for Mac is a VNC client. I recommend Chicken VNC (this is a derivative of Chicken of the VNC and is better because it supports tunneling through ssh).
VNC does not compress as efficiently as NX but if you have a broadband connection, the response is satisfactory. X2Go is new and somewhat spotty still, but when it does work, it also provides sound (but that also is intermittent).
For Windows, TightVNC performs well but is insecure since everything passes plain-text unless you setup an ssh tunnel using putty or other windows ssh client. The risks with TightVNC are essentially the same as those of telnet or rlogin, everything is passed over the Internet plain-text.
I’m working on support pages for these newer products and always looking for something more solid, but on the bleeding edge, that’s sometimes how things are.