I wanted to share a little script that turned to be very useful for me.
Get-ExchBuild.ps1 lists the build numbers for all versions of Exchange listed in the official TechNet page, but from the convenience of the PS command line.
You can run it without parameters to return them all, or restrict the output to certain versions of Exchange (tab autocompletes). Specifying the -Cloud parameter returns the Exchange build of the mailbox server hosting your Office 365 mailbox, if you happen to own one.
Just create a text file, paste the script code from here, and save it as Get-ExchBuild.ps1 in c:\windows or anywhere in your $env:path. Your execution policy should be set as RemoteSigned in order to run local scripts on your system.
Due to its dependency on the TechNet page it's likely that the script will break if there's significant changes in its content. I'll try to keep it running.