title: Real-time collaborative drawing whiteboard in HTML5/JS and websockets?
body: <p>I'm trying to put together a small(ish) summer school project for some of my advanced students and am researching how to do it best and what to use - hopefully somebody here could point me in the right direction.</p>
  
  <p>What we are interested in is researching if HTML5 came far enough to create a real-time collaborative drawing whiteboard in it - purely by using web technologies without plugins (so CSS, HTML5/DOM and Javascript). What we'd ultimatelly strive for is this - for example have an online canvas/page on a central server displayed on a big screen in the classroom. Then our students/users would take out their smartphones, load the page in their mobile browsers (I'm perfectly ok with limiting this to webkit mobile browsers for now) and draw on their screens with touch/fingers (or on PCs with the mouse - guessing this doesn't make a lot of difference) and it would get updated in real time for everybody - both on their screens and on the central big screen in the classroom.</p>
  
  <p>I'm guessing push/get requests would be too slow for this - could it be solved by websockets? Does anybody have any good JS libraries to recommend for this? </p>
  
  <p>Also what would the ideal (but easier for students to understand) architecture look like. Lets say you have 30 simultaneous users in a clasroom - each of them would connect with websockets to the server and the server would pool/combine all of their requests into one and then return the combined file (some sort of minimal JSON or even just coordinates) for every connected user?</p>
  
  <p>Would websockets and (I'm guessing) canvas be able to take this? So that everything still looks snappy? Are there (jQuery-like) JS libraries available to make our lives easier - or do you think its something thats too complex for a 2-week summer school project?</p>