Rust and Zig Combined

Why would someone use both Rust and Zig in the same project? Rust is complex and famous for its borrow checker's memory safety benefits, whereas Zig is famously simple and has no borrow checker. Wouldn't a project want one or the other, rather than both together?

The compiler for the Roc programming language intentionally uses a combination of Rust and Zig. As it turns out, the circumstances that make this a good choice are not as rare as you might think, and the differences in memory safety between Rust and Zig are also not as big as you might think.

Come learn about the surprising benefits of combining two languages as different as Rust and Zig!