The eleVR people have some interesting demos in this regard, where you program from inside the VR system. That might be the best way to try things out and conduct the "foundational work"
Hmm, I was ambiguous there. What I had in mind for "foundational" was, for example, constraint engines for GUI layout. Now we have CSS. But there was something like a decade, where we knew constraints were a good way to do UI layout, but there weren't available constraint engines. Each major language had odd bits of abandonware zombies, academic or hobby projects, with code which might or might not be online, or be buildable, or be licensed for use. So we had to wait for market incentives to change, and some non-trivial work to be done, before we had the foundation element of GUI constraint-based layout.
An Alto analogy might be bitmapped fonts and display.
A current analogy might be 3D dynamic structured graph layout. There's been a lot of research over the years on how to dynamically modify graphs without disorienting viewers. And on how to layout graphs within graphs, and with various spatial constraints. But last time I checked, the github cupboard was bare. So say you want to write a really wizzy todo app with complex dependencies. Well, first you read two decades of graph layout papers; then you write the graph layout library no one else has gotten to yet. Foundational work on our collective todo list.
