Quickly Figure out a SharePoint Farm Version
Here is a nice quick script that you can run on any SharePoint site to determine the version of SharePoint the farm is running. Thanks to the $cript Fanatic Blog - Shay that helped me construct the query (https://scriptolog.blogspot.com/2007/08/query-http-status-codes-and-headers.html)
$url = "https://sharepoint"
$xHTTP = New-Object -ComObject msxml2.xmlhttp
$xHTTP.open("GET", $url, $false)
$xHTTP.send()
$xHTTP.getResponseHeader("MicrosoftSharePointTeamServices")
Output: 14.0.0.5128
If you want to have some more fun, check out all these SharePoint sites in the world (https://www.wssdemo.com/livepivot) and see which versions they are running. Enjoy