Lots more good info from you, thanks! I agree that Microsoft is clear about product life cycles, and generally quite generous with those life cycles too. Now that I see the correct life cycle info, I have no argument with MS re the FoxPro support drop. And yes, I noticed (and already used) that life cycle page to look up a few other MS products.
Re MS Office 365, I am actually a subscriber to Office 365 Home, and even that edition includes Access, which greatly influenced my decision to subscribe.
I'm delighted with 64-bit BigInt, and will look at all those links you supplied. Thanks again. I recognize that there is still the overall question of what would suite my purposes best. To be, or not to be, MS and/or Windows dependent will remain a question in this whole deliberation.