What is the math behind popular Bitcoin graphs? I want to graph Namecoin (or similar *coin) technologies?
The math behind those graphs is pretty simple, the main problem is crawling through the data and creating readable images automatically.

Difficulty (red line) can always be read from the generated Blocks, no problem there.

1/3/7/14/whatever-window estimates I assume are calculated by counting how many Blocks were generated in a given time period and at what difficulty. In general I guess it should be:

Estimate = (Difficulty * MeasurementTime) / (10 minutes * BlockCount)