First, Congrats on the release!

Do you know if Goose is the first time something like this has been done?

In this particular combination, most certainly.

There is lots of prior art on the individual parts of the design, e.g. "regions" and various stack languages etc, see: https://github.com/aardappel/goose/blob/master/docs/design/p...

Part of this is that 64-bit address spaces make this design practical, and almost all languages in use today were designed with the limitations of 32-bit in mind. Once you can assign arrays huge amounts of address space, you don't have to realloc, which gets you stable pointers, and a lot of the other Goose features.