Planet Lowyat

Who Is Hosting is a tool that enables you to find out who is hosting any web site. Simply type in any domain name, and you’ll get a link to the company that’s hosting this particular domain. It’s that simple! Check out the FAQ and our blog for more info.

Who Is The Owner is a free online tool which enables you to discover who is the owner of any domain by querying more than 350 whois servers in the world.
Simply type in any domain name and you’ll get all the available information (name, address, phone, …) about its owner.

MyIpNeighbors - For those on shared hosting, myIPneighbors IP search is a great way to find out who your neighbors are or just to see how many other websites your hosting company hosts your server. Is your website packed into a crowded host with hundreds of other sites? Or is there questionable content being hosted side by side with your site? If so, it may be time to look for a better host.

BuiltWith - Unlike the above tools, BuiltWith focuses on the website itself. With the help of BuiltWith you can instantly lookup all implemented technologies behind any website (Google, Digg, Reddit, Youtube, yourdomain.com, etc.). If you ever plan to replicate some website, this is the tool you need. Among other things, it will aso give you a basic SEO profile.

Source: MakeUseOf