The evolution of Mac app window corners

This is a follow-up to my recent blog post macOS Tahoe windows have different corner radiuses . I’ll start by noting that Apple goes into more detail about the new Tahoe design in the WWDC 2025 session video Build an AppKit app with the new design : The floating sidebar, along with the toolbar, demonstrate a key element of the new design system: concentricity. Each element is designed with a…