joelanman, (edited ) I think the GOV.UK Design System is very close to this. Widely tested, accessible, tech-agnostic, just needs to be more theme-able (edit - including internationalisation, thanks @whitingx )
joelanman, (edited ) I think the GOV.UK Design System is very close to this. Widely tested, accessible, tech-agnostic, just needs to be more theme-able (edit - including internationalisation, thanks @whitingx )