If I broke anyone else's implementation, let me know. Added the capability to search the Primer at the bottom of the left nav. Added multilingual capabilities. Currently only supports English. Some changes are harder to notice than others.
Multilingual support is also on the drawing board.
They are being removed. It's your feedback that keeps making this better. I'm trying to find the time to rewrite the first few sections to make this a bit more helpful to people a bit less experienced in this field. Daryl's Subnet Calculator. See how the computer uses subnet masks.