> I also feel like this is another thing that the "fast ring" of the EU should do together. Take Estonia's stack as a base, and then countries like Sweden, Denmark, Finland, The Netherlands adopt it and co- develop it. Make it extensible for the bespoke things the countries need, and every few years check which bespoke extensions can actually be generalized and modularized.

Argentina's ministry of education did something like this with university software. The one used by students to sign up and by teachers to track grades, etc. There's a single open source modularised, customisable system made country-wide, and public universities customise it to their needs.

Before this initiative, every university was implementing their own software from scratch. In many cases, different faculties (e.g.: Engineering, Natural Sciences, Humanities, etc) each had their own software development teams developing their own independent software stack.