Free the Foxes

It is essential to have your users operate a browser that supports an appropriate standard on how things are displayed and how things function. Free the Foxes is FREE and is roughly only 25K in size (including JS, CSS and images) and is almost completely customizable...

source: http://www.freethefoxes.com/
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JS Bin, a Collaborative JavaScript Debugging

(nothing to add, it'll be redundant)

source: http://jsbin.com/
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