As promised, Microsoft has now opened their Office Insider program to our friends with Office for Mac.
Office Insider is Microsoft’s new ‘preview’ program. Members get advance access to new releases of Office for Windows/Mac
Access to Office for Mac insider is through Microsoft AutoUpdate. Open one of the Office 2016 for Mac programs, choose Help | Check for Updates. You need an Office 365 subscription, not a one-off/perpetual licence install.
Office for Windows works a little differently, see Inside Being An Office Insider
