Rust 1.98.0 reached stable on August 20, and its headline is a corner of the language that had been half-finished since 1.0: variadic functions. Rust could already call C variadics like printf, but it couldn't define them; the now-stable c_variadic feature closes that gap, which matters mostly to people writing FFI shims and C-compatible libraries that have carried nightly-only workarounds for years. Alongside it, inline assembly gains 128-bit integer operands, and a derive-macro bug in PartialOrd that had been open since 2018 finally got fixed. None of this is a reason to drop what you're doing — it's a maintenance-and-FFI release rather than a headline feature drop — but the c_variadic stabilization unblocks a specific class of binding crates. The lifetime-coercion change, which allows shortening a &mut lifetime during an unsize coercion even in an invariant position, is niche but removes another paper cut. Toolchain updates arrive through rustup as usual.