Roughly dependency-ordered todo list:

# Minimal core language:
* [ ] *PROCESS/MCALL*
* [ ] EVAL; initial interpreter and REPL
* [ ] atoms, global bindings, normal FUNCTIONs
* [ ] *GC*
* [ ] local bindings
* [ ] control flow
* [ ] advanced FUNCTIONs; macros
*Bold*: APIs everything else is built on, impl as early as possible

# Other essential language components:
* [ ] atom OBLISTs, BLOCK
* [ ] INTERRUPTs
* [ ] DECLs checking
* [ ] PACKAGEs
* [ ] STRINGs
* [ ] checkpointing?
* [ ] FFI

# Bonus features:
* [ ] package management?
* [ ] COMPILE function?
* [ ] I/O threadpool / BLOCKED process state?
* [ ] DECL TEMPLATEs?
* [ ] optimizing AOT compiler?
* [ ] heapstacks?