A list of servers can be obtained using windows command prompt (cmd) or powershell (ps). CMD and PS both provide Server Name and Instance Name, however, powershell provides two additional fields: IsClustered, and SQL Server Version. One challenge I have noticed is that running these commands from my local machine only returns a short list with names that look like computer names and not server names. I had to run the commands from a production server, a QA server, and a development server to obtain the server lists from those environments. There must be some network separation between them, which I am still investigating.
CMD: OSQL -L or SQLCMD -L