Well, the OTHER useful example is STEPS project of the VPRI institute which claims that you could build the equivalent of our modern desktop software which much

Well, the OTHER useful example is STEPS project of the VPRI institute which claims that you could build the equivalent of our modern desktop software which much, much less code. The big issue with this project is that AFAIK no code is available.. But it could be an interesting way: maintain an existing enormous codebase and build from scratch in parallel another one, then meet at the middle.