How can I generate legal random chess setups? Is there a free online website that attempts to generate "legal" random chess setups X amount of moves into the game?
I stumbled upon Chess Hero.  It looks very nice, but it is not online.  Per the website:


You supply a set of PGN files
The program picks random positions from the PGN files and challenges you to guess the best move computed by a chess engine
On every attempt you are given a penalty (the difference in score between your move and the engine best)


The software can be found here.