The rails-core guys would frequently hit a site, and then pull down the rails logo they silently dropped into everyone's directory. That or they'd look for Mon

The rails-core guys would frequently hit a site, and then pull down the rails logo they silently dropped into everyone's directory. That or they'd look for Mongrel headers. Also, eventually all the employees at these companies leave and then you hear about who's using what because the employees tell you. That's different than say a web server or chat protocol where you don't have to say at all what server it is, and it's usage is just about configuration rather than daily coding on it. With infrastructure nobody should really be talking to you if you've done your job right.