An iOS and macOS audio visualization framework built upon Core Audio useful for anyone doing real-time, low-latency audio processing and visualizations.

Sample code for Bob McCune's Learning AV Foundation book.

The Amazing Audio Engine is a sophisticated framework for iOS audio applications, built so you don't have to.

MIDI Library for Swift and Objective-C Mac and iOS apps.

Apple ARKit example app

iOS/OSX DSP for audio (with Novocaine)

Hook up MIDI software and hardware and pass MIDI data between them, applying assorted filters on the way.

On-screen MIDI keyboard with hotkeys support

A great start point for making AUv3 MIDI sequencer apps.

An AUv3 MIDI plugin. See the blog post