Units
A unit is a named part of root. Your own unit is the place for words that every tab should see and that should survive reboots.
"mine" unit
This creates an empty unit at the end of root and opens it in scrawl. Write [ "hi" say ] :greet, save with Ctrl-S and quit with Ctrl-Q, and greet is available in every tab.


Rules
Unit names are 1 to 20 characters of lowercase letters, digits and -, and must be unique. Root can hold up to 32 units.
Order
New units are always added at the end, so they can use every other unit and editing one only rebuilds itself. Reordering or removing units requires changing root/ in the source tree and rebuilding the kernel (development). From inside the system, a unit can only be emptied.
A later unit overrides an earlier one that defines the same word, and redefining a built-in prints a shadows: warning. All of root has to fit in one 1 MiB slot. A program also needs an entry in the apps list to appear there.
subverge