[lazyjones]

The X way of doing window updates became impractical with common graphics-heavy applications like web browsers. I could already feel this in the mid-90's when opening a browser window on a 19" NCD X-Terminal took several seconds over 10mbit/s Ethernet (noticeable because most other X client applications at that time used drawing primitives and appeared instantly).

For modern applications (graphics- and video-heavy), VNC/RFB seems like a much more suitable protocol, although I haven't really kept up with the latest X extensions that probably cover some of these applications.

Personally, I liked the X architecture more (despite X's inherent complexity) and expected it to become more popular with cloud-hosted applications etc., but as applications and GUI toolkits evolved in an unsuitable way (i.e. not using X's primitives), it's probably time to let go. Or to build a proper GUI toolkit first...