web app for implementation footprint of web apps (!)

aloha, I was wondering (http://inormalized.com/2008/8/13/web-app- implementation-footprint) if there is any sort of web app out there which holds information about tools used on other web apps.

Like eg nubyonrails.com has

Manufactured with

    * Merb     * HAML     * LowPro     * Prototype     * Nginx     * Ruby     * Vlad     * Git

is there something like that out there that (google doesnt know about;) )?

best regards, Spyros