Will Always-on HAS ALWAYS BE installed in a Cluster environment?

Hello:

I understand High availability includes Windows Cluster, But I have a simple question:

Can I Install or deploy/configure Always-on in a NON windows CLUSTER environment?.

Just have 2 servers, might be same or different data centers, of course in a Domain, can I install/configure Always On from one SQL Server instance to another SQL Server instance that DO NOT reside on a Windows Clustering nodes?. Just plain Windows boxes?.

Thanks