I believe that I have a side project brewing, and I find it likely that I'll use Zig for it. Here's an intro if you haven't heard of it before, and here's something absolutely amazing to me as a particular kind of language purist.
I mean, there's nothing wrong with hygienic macros (see Rust or Lisp) which can accomplish pretty much the same thing, but they explicitly exist in a different universe than the program they're working on. Sure, that makes them more powerful, but Zig's
comptime seems to be much more in-line with the rest of the language; it works exactly as you'd expect—what you wrote gets evaluated at compile time as far as is possible.
The only other language I've heard does something like this is Jai, which shares some of its goals with Zig, but it fills a different niche and is not yet widely available whereas Zig is.