http://languagegame.org/pub/booltable/booltable.html
Boolean logic is a basic knowledge for all programmers. The idea is very simple and straightforward, yet still it often annoys you a lot. One of the reasons might be that boolean logic is not continuous behavior, and just a bit of changes makes completely different result. This is why it is hard to grab whole character of a boolean expression, I think.
This tiny program shows every possible state of a boolean expression to make sure your logic is correct. I wrote this to help me reading a textbook about logic, and to make programming nested condition statements easy.
One nice thing is "permlink" function. You can bookmark your favorite boolean expressions to play again. It works even in file URL as this is written entirely in Javascript. So feel free to download to your local disk.
Here are a couple of examples to link boolean tables:
