The latest Mame release - 0.227 - is supported for macOS 10.14+. While earlier macOS versions are just one release behind, at 0.226.
Is there a particular reason why 10.13 and below is on 0.226? and only 10.14 and above has 0.227?
I'm curious will the older systems have an up to date port in due time?
I'm overly just curious why it isn't synced across the board and of the workflow.