Is there a way to check which server OS a particular site is running. For example from linux command line. Maybe via telnet? But all I can get from "telnet www.google.com http" is:

Trying 209.85.173.104...
Connected to www.l.google.com.
Escape character is '^]'.


Can somebody dwell on the subject if possible at all?


Question: Unusual Differential Equation
Answer: hint: as long as $yy' \ne 0$ you can divide through by it, giving:
$$\frac{y''}{y'} + n\frac{y'}{y} = 0
$$ 
giving $ln\; y' = -n \;ln \; y + c$