So.. Managed to get tales working with appengine. Here's a quick app I made in the last hour:

Who's who on Sidewalk - which Let's you map and remember a full name to a sidewalk username.

I am not posting a new build yet, since tales dev mode does not yet work with appengine's server.

Also the current plan is to use jiql. I would want to know if any of you know of any limitations in using jiql?

So since now we have an app running on appengine which would help us with nice sandboxing, my be we can think about building that playground :)?

I'm assuming you'll use Java FFI to connect to the app engine, right? I'd love to help out with app engine but I'm atm still busy debugging miglayout and doing some exams. Besides jiql and tales what other technologies would you use?

Besides jiql and tales what other technologies would you use?

You mean for playground? I don't even think jiql is required. Just plain Fantom and may be tales.