I toyed around a with Bing Webmaster Tools: https://www.bing.com/toolbox/webmasterAnd then checked access.log. One referrer was http://www.bingsandbox.com/Link: http://www.bingsandbox.com/whois gives following result (web link: http://whois.domaintools.com/bingsandbox.com)Domain Name: bingsandbox.com [..]Tech Organization: Microsoft Corporation [..]Tech City: Redmond [..]Name Server: ns3.msft.net [..]Information about: https://www.bingsandbox.com/From: https://www.sslshopper.com/ssl-checker.html#hostname=www.bingsandbox.comCommon name: a248.e.akamai.netSANs: *.akamaihd.net, *.akamaihd-staging.net, a248.e.akamai.netOrganization: Akamai Technologies, Inc. (really don't know how to do this from command line)
What is bingsandbox.com?
domains;web crawlers;bing;referrer;whois
The sandbox is the name normally assigned to a test environment (playing area) for a project. Given that http://bing.com is the Microsoft search engine and the whois reveals the domain is a Microsoft property, I assume that's a test version of the search engine.It's likely it's used to deploy and test new features in a production-like environment without affecting the main search engine. This is useful because, if something goes wrong and the sandbox crashes, this is not likely to affect real users and the real production app.