Friday Flash Java Fun - 'Building Houses With Side Views' Entertaining Java game/exercise/doodad. [more inside]
posted by le morte de bea arthur on Jun 13, 2008 - 31 comments

"Once you've constructed your Hexapawn opponent, it's time to start playing against it... If you play this game repeatedly ... you'll quickly notice that your matchbox opponent plays better and better until it is unbeatable!" Martin Gardner created a game called Hexapawn, and also devised an artificially intelligent opponent you can build yourself out of matchboxes and colored beads. Bonus link: An interview with Martin Gardner.
posted by Fuzzy Skinner on Apr 1, 2008 - 17 comments

PhET - Physics Education Technology offers this astoundingly large library of online physics simulations. Play orbital billiards. Land on a cheesy moon. Experiment with sound. Or try more advanced quantum physics simulators. Still bored? Try the "cutting edge" catagory. Here's the complete index. (Warnings: Frames, Flash, Javascript, Java applets, graphics, sound, quantum timesuck.)
posted by loquacious on Feb 3, 2007 - 7 comments

A View from the Back of the Envelope - approximations and the fun behind them.
posted by Gyan on Oct 18, 2005 - 25 comments

Thinking Machine 4 explores the invisible, elusive nature of thought. Play chess against a transparent intelligence, its evolving thought process visible on the board before you.

From Martin Wattenberg (with Marek Walczak); they have been noted here before.
posted by e.e. coli on Oct 27, 2004 - 11 comments

"WARNING!!! The puzzles on this site are very difficult, and most require the use of a good spreadsheet program in order to solve them. It will take many hours, perhaps days, to solve each puzzle..."
posted by limitedpie on Aug 11, 2004 - 7 comments

Mathematik and Dynamical Systems. Mathematical visual effects and games, mostly javascript-based.
posted by donth on Jan 10, 2004 - 5 comments