I made a web interface for my LPD8806 led matrix. this is done on a raspberry pi . I used lighttpd and fastcgi as “server”. Client side I used some jquery/ajax and simple html5 canvas elements. I must say I’m pretty happy with the delay… it’s only ±100ms. I first tried it with normal cgi but then the responsiveness was not good enough (400-500 ms). I’ll make a full featured web interface for my led display so I can make “play lists” from anywhere. I didn’t try real drawing (not pixel/pixel) yet because for that I need some buffers (client and/or server side) to handle the outgoing/incoming pixel data.
http://www.youtube.com/watch?v=dc1SXHSOcOQ
Awesome! I made a similar project for my living room but chose to use websockets to communicate with the raspi / lpd8806 pixels. It might reduce your delay even more. Here is the code if you’re interested: https://github.com/shlomozippel/livingroom/tree/master/lpdserver
I think websockets might be very cool indeed because it let you push animations etc to the client. However I only know how to implement websockets with node.js and didn’t try to install it on my raspberry. I will have a look at your code to see how you done it.