using browsers programmatically

I want to build开发者_如何学Go the following back-end service:

For each call to the service, spawn a web browser that loads a webpage (including flash) and returns a screenshot of the page to the caller at intervals (ie every 3 seconds) until the caller disconnects. This needs to scale for many callers (thousands perhaps), each of which needs its own browser session.

When I decided I needed to build this program, I was surprised that I had basically no idea how I could do it.

On stackoverflow, I found the following link which looks promising: http://www.genuitec.com/about/labs.html

Any other ideas?

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You can use XULRunner (Mozilla engine) on your server side. I'm in doubt though that this solution is scalable.