Using cURL, you can easily grab some information about the server who’s running a Web site.
To get all the possible information, simply use (replace domain.tld with the actual domain name) :
curl -s -I domain.tld
You can also can just output the server info like this :
# curl -s -I microsoft.com|grep Server Server: Microsoft-IIS/8.5
NOTE : Not all server will output the same amount of information and some may be hiding or providing false information for security purposes.