Is there any website that allows you to choose an algorithm, code it and visualise how it works? I would like to do some practical implementation of a planning algorithm (of course, something a bit simple and easy).
Is there any website where I can pick an algorithm (e.g. A* or hill climbing), code it, and visualize how it works/executes?
The site doesn't necessarily need to be restricted to planning or search algorithms.  For example, in the context of machine learning, I would also like to be able to pick the learning algorithm and model (e.g. linear regression), code it, and visualize how it works.
Not planning, but this is a visual in-browser neural network for your interest:

http://playground.tensorflow.org/