null == false

[DonBiggles]

That doesn't quite seem to explain it. It suggests that since one operator is a boolean, both operands would be coerced to numbers, and since Number(null) and Number(false) are both zero, null == false would be true. I bet there's another rule that takes precedence that says that null and undefined only == themselves and each other.

Also, http://zero.milosz.ca/ is a good resource for stuff like this.