How to find out which webserver is being used to host a website

https://www.netcraft.com is an interesting site for a number of reasons. The site includes the facility for you to enter the URL of a site which you'd like to find out which webserver software is being used to host it. In addition to many other useful pieces of information provided by Netcraft uptime statistics are provided too. Many sites running Microsoft Internet Information Server(IIS) have achieved uptime exceeding a year. This may come as news to some who may be surprised to hear that IIS can be both secure and reliable enough to maintain service for such duration.