AudioKit is described as 'is the leading open-source audio framework. It powers millions of app installs. AudioKit allows developers to quickly add professional audio functionality to iOS, macOS, and Apple Watch apps' and is an app in the Development category. There are seven alternatives to AudioKit for Windows, Linux, Mac and Self-Hosted solutions. The best alternative is JUCE. It's not free, so if you're looking for a free alternative, you could try PortAudio or RtAudio. Other great apps like AudioKit are FMOD Ex (Free Personal), OpenAL Soft (Free, Open Source), SoLoud (Free, Open Source) and KFR (Freemium, Open Source).
RtAudio is a set of C++ classes that provide a common API for realtime audio input/output across Linux, Macintosh OS-X and Windows operating systems. RtAudio significantly simplifies the process of interacting with computer audio hardware.
OpenAL Soft is an LGPL-licensed, cross-platform, software implementation of the OpenAL 3D audio API. It's forked from the open-sourced Windows version available originally from the SVN repository at openal.org.
KFR is built for developers who need a powerful toolkit for audio and DSP applications. The framework is packed with ready-to-use C++ classes and functions for various DSP tasks from high-quality filtering to small helpers to improve development speed.