iMac - best operating system?

I have a mid 2011 iMac that could become my openHAB server since it is currently just gathering dust. What operating system would be best to run openHAB - either macOS (El Capitan) or I could convert it to Linux. Am I likely to run into unexpected issues either way?

just my personal assumption, but I think most people run it on raspberry pi, which means Linux. not sure if the foundation is tracking any usage data.

you can run it on your Mac.

I tested it on my Mac. and then installed on my server

check the link to see.