Interesting quote by James Gosling (of NeWS fame, among others):
"I think that a more viable solution in the long run would
be to replace the X protocol with a very simple pixel copying
protocol that uses the user-level rendering libraries in the
application to render to a local image buffer, then copies the pixels
over the net in something that looks vaguely like a video stream.
There are a variety of compression hacks that make this
surprisingly efficient – this is essentially what the SunRay product
does. Some analysis has been done that shows that this uses
essentially the same bandwidth as the X protocol, if done well."
From "Window System Design: If I had it to do over again in 2002."
Their argument is "A simple pixel encoding protocol requires only modest network resources (as little as a 1Mbps home connection) and is quite competitive with the X protocol."
This may work fine on a dedicated gigabit network, which is where SunRay lives, but it does not work at all on a slow, possibly high-latency, link. To see for yourself, try running any gtk or qt app over an ADSL link or even a local wireless network, and enjoy the slide-show. Apps using server-side font rendering, on the other hand, work nicely under these circumstances.
"A pixel copying protocol" would describe VNC and RDP as well, wouldn't it? By running any GTK / Qt app over ADSL you mean running them using the X11 protocol?
"I think that a more viable solution in the long run would be to replace the X protocol with a very simple pixel copying protocol that uses the user-level rendering libraries in the application to render to a local image buffer, then copies the pixels over the net in something that looks vaguely like a video stream.
There are a variety of compression hacks that make this surprisingly efficient – this is essentially what the SunRay product does. Some analysis has been done that shows that this uses essentially the same bandwidth as the X protocol, if done well."
From "Window System Design: If I had it to do over again in 2002."