- very solid build system (the build config file(s) are written in zig so you dont have to learn another language for the build system (looking at you, makefile)) that has crosscompilation builtin (with one compiler flag)

- language level errors, like, errors as first class citizens. forces you to handle errors, but without much mental or syntactic overhead (you can re-throw them with `try myfunction()`), also results in a unified interface

- no implicit conversions

- looks high-level (modern sytnax that is easy(ish) to parse) but as low level (or lower) than C, no abstractions that hide details you need to know about when programming (similar to C)

- C interop, so you can just add zig source files to a C project and compile it all with the zig toolchain. Zig can also parse c headers and source files and convert them, so you can include c headers and just start calling functions from there. For example, using SDL is as simple as pointing the toolchain to the SDL headers and .so file, and the sdl headers will be translated to zig on the fly so you can start with SDL.SDL_CreateWindow right away.

Not to mention memory leak detection, crazy fast compilation times, slices and a built in C compiler so your code can seamlessly integrate with an existing C code base (seriously no wrapper needed).

Zig is really really awesome. The only thing holding it back from mass adoption right now is that it's not finished yet, and that shows in the minimal documentation. That said, if you're comfortable tinkering, it's completely capable of production uses (and is already used in production in various companies).

Real enums, modules, etc.

A compile-time execution system (effectively replaces the preprocessor/macro system).

Syntax that is easier to `grep -r` for without complex regex.

Tests are a first-class citizen.

Safer type system.

Really, just a bunch of things that should've been added to C 20 years ago.