ZZ's whole goal is to transpile to C, which (as their website mentions) has some practical advantages. Consider exotic hardware platforms where there's a vendor

ZZ's whole goal is to transpile to C, which (as their website mentions) has some practical advantages. Consider exotic hardware platforms where there's a vendor-provided proprietary C compiler and no other choice. Dafny has a slightly different emphasis, as it's about formal verification, so it's more competing with Ada SPARK than with mainstream languages. I can't comment on the general ergonomics on ZZ and Dafny as I've not tried them out, but presumably they're going to be well behind a language like Java with its huge ecosystem of IDEs etc. Neither seems particularly mature, either, so I wouldn't bet the farm on them. > Is it better to write ZZ or Dafny code than to write Java, Python, Haskell, Rust, or Swift code? If you've got the choice and you're just trying to do 'normal day job programming' I imagine that yes you'd be much better off just using Java. If you want a language that's quite like C or C++ but much better regarding safety, there are Rust, Zig, and the too-often-overlooked Ada language.