Microsoft has a Windows Insider test program. It has an Office Insider test program. Though it hasn't promoted it much (yet), the company also has a Microsoft 365 Insider program.

I saw a link to a Microsoft 365 Insider program sign-up/sign-in page thanks to The Walking Cat (@h0x0d) on Twitter.

From that page:

"As a Windows Insider or an Office Insider, you likely have already gotten your hands on everything we’re showing you at Microsoft Ignite. Across both programs, we’ve received amazing feedback and designed some great features together, and we’re not done yet.

We know that all of you who work in IT want to help us create what’s next and so, we are announcing a new initiative for tech heroes like you. If you’re all in on Windows and Office and are looking to speed up your digital transformation even more, we invite you to join our new Microsoft 365 Insider Program.

By signing up for this program, you will be getting all your enterprise news, events and community in one place as well as a clear path into what’s next for collaboration, productivity and security.

In the coming months, we’ll be looking to your help to create this program to make you even more successful in your career and help make your business more competitive.

Use this Microsoft 365 Insider program as part of your deployment to make sure you’re ready for the future of Microsoft."

Read more: The Microsoft 365 Insider test program is open for business | ZDNet