TIL qrtool, a command-line utility for encoding or decoding QR code. Impressively, it can even display generated QR codes directly in the terminal.

TIL QRCode, quick and beautiful macOS/iOS/tvOS/watchOS QR Code generator/detector library for SwiftUI, Swift and Objective-C. It supports SwiftUI, Swift, and Objective-C and seems far more robust than CodeScanner by @twostraws (Paul Hudson).