Yeah, exactly that! I'll have to check out Wappalyzer.

The code is written in coffeescript, and some key npm modules are:

- https://github.com/caolan/async

- https://github.com/brycebaril/node-tokenthrottle-redis

- https://github.com/rs/node-netmask

I was at one point using https://github.com/tjfontaine/node-dns for the hostname lookups, but it was significantly slower that the built in dns module, so I ended up wrapping that with my own timeout logic.