SensibleSideButtons makes your mouse side-buttons behave like bona fide navigation keys. Navigation now works in practically any application with a history, even if there aren't any keyboard shortcuts bound to forward and back. Navigation commands are sent directly to the view under your cursor, alleviating mistakes and even (hypothetically) allowing multiple navigable sections within a single window to be controlled independently. There's no blinking menu bar, no annoying noises, no fear of errant keyboard shortcuts messing with your workflow. Best of all, the code is native, clean, and very simple. All we're doing is dusting off some slightly forgotten parts of macOS.