Show HN: a free multi-user whiteboard with unlimited, zoomable surface

The front ends seem to get desynchronised when two incompatible concurrent edits happen; this is a difficult issue to resolve, but one solution would be to change the data flow so local edits are drawn by the client on a transparent canvas, get sent to the server, and then get drawn on the underlying main canvas only when they are sent back from the server. The transparent canvas can be reset by the client at that point (you might need some synchronisation mechanism for this), so all users will end up having consistent state once edits have been processed by the server.

To me the zoomable, unlimited surface part is what makes it super neat. I might actually use it if I had some way of typing text on there..

I suppose for a tablet it is awesome though.

I would definitely use it. Add a [T] icon for texts as writing with the mouse is meh!

Very cool. There are some minor issues though.

Here is my sketch: http://sketchub.com/view/d4b8fcb36fe4b078b100069bafebd352

I'm using a Thinkpad with Wacom enabled display and stylus. It 'should' say 'hello world' 3 times and have an underline after each one.

In the saved and view only link, it shows a 4th 'hello world' on the left and more slanted. It was erased before my real test.

It seems to miss certain strokes as you can tell by the sketch. Mainly straight lines. This might have been caught as trying to move the sketch area, but it did not move or register the line.

(As a control test to check display and stylus, I wrote the same text in OneNote and it was handled fine.)

I work in a distributed office, and over the past few days I've been trying to find a "concept mapper", which helps us to make projects more concrete through flowcharts etc. The problem that I keep on facing is that the web apps which dominate the current market just don't cut my needs. They don't allow for proper exploration, and collaboration is a frustrating progress. We would gladly pay for a tool that doesn't get in our way and just lets us all communicate.

I think that you will find a ready market, if you can solve the thorny problem of communicating projects, which involve several interconnected parts/ideas.

I know for a fact that I'll buy it.

Yes, you need text and images. The company I work for has been looking for a simple, fast, and good solution to make notes over webpage wireframes. I think this could be it!

sum up your pitch to make it easier for users to get what you are pitching.

"collaborative zoomable user interface to create sketches" is the same as "multiuser whiteboard" just easier to get.

Very nice - you should do what I figured out for a project - momentum when there is a big action, and fine control for small actions - if I scroll the wheel dramatically, give me some momentum on that zoom - if I scroll it slowly, no momentum and fine increments (like you have now)

The way I did this in javascript was to create an array of zoom in/out and the four directions - then you add or subtract from the array based on intensity of gestures over time - even keyboard action keys (+/-) can have momentum this way by adding when there is continuous keypresses - I was pleased how it turned out in the end.

I would have liked the ability to change the line thickness, to work around you'd have to zoom out or in depending if you wanted a line thicker or thinner with the latter being particularly difficult as it's harder to keep track of where you are in relation to the rest of the page.

Cool stuff!

I've looked a bit at what it uses: shapes drawn are vectors, the app uses Raphael (http://raphaeljs.com/) for drawing, and Pusher (http://pusher.com/) for whiteboard syncing.

Cool. I'd love to be able to upload an image, or series of images, to draw over.

Great tool ! Simple and focused. Maybe two things a little more helpful : 1. The ability to press Ctrl+Z to undo 2. A global reset button (not so important as we can refresh the page)

I would love to try this on an iPad with a pen.

This is awesome, I'd just like to have a tool to write with my keyboard.

this is pretty neat, from a designers point of view here are some things I'd suggest:

- something like a photoshop navigator where you see your zoom level vs your current canvas. Currently it's quite easy to zoom out a lose your stuff. - alternatively have a zoom % and return to 100% and center - As well as the current freehand drawing style, have a version that straightens the lines for you. - keep line thickness at any zoom level so it's not so bad when you zoom back in (although I can think of nice uses as it is) - write text

I'm not sure if it's just me, but there seem to have been a few very similar sites/ideas posted here over the last few days.

Well done for making it work in IE though =)

If this is like switching between layers using your scroll-wheel, let us push part of the sketch back or forward, scale down or up.

Awesome, but with more keyboard shortcuts I'd use it all the time. (CTRL to pan, different keys to select different things)

Not working here on my HTC Desire with Android 2.2. Looks like there is no way to draw.

Looks great on iPad, well done.

Infinite zooming is nice. How is it implemented? I would like it as a library.

Looks a lot like Khanacademy's Scratchpad they recently open sourced.

Very cool, unlimited zoom is an awesome idea

If you zoom in too much, it's very lagging. Strange, It should be when zooming out (FF 5.0)

find the hidden word: http://sketchub.com/xuugfkbshr

genius