A: 

No, not really. Webservers will return you an HTTP response, which generally won't include details of the server configuration.

Dominic Rodger
+1  A: 

Builtwith or Quarkbase may help in getting these info

Amr ElGarhy
Neither of those have any idea what the specs are of the servers running stackoverflow.com.
Dominic Rodger
See http://builtwith.com/?stackoverflow.com or http://www.quarkbase.com/stackoverflow.com
Dominic Rodger
+1  A: 

You could use HTTPRecon :

http://www.computec.ch/projekte/httprecon/

Might give you some starting point

Darknight
+1  A: 

Not really without installing something on the server that will expose that information. The best you can get is the version and type of the web server (e.g. Apache, IIS, etc). Inner details are not exposed. Security risk amongst other reasons.

There are many packages out there that you could install on the server, so long as you are okay exposing that publicly. Ideally hide it behind an obscure URL and/or password protect it, IP restrict it, or place it under an administration part of your site.

e.g. for PHP, I quite like phpSysInfo

tjmoore