libremidi

libremidi is a cross-platform C++20 library for real-time and MIDI file input and output. It supports MIDI 1 and MIDI 2 and in particular is the first cross-platform library to allow access to the macOS, Windows and Linux real-time MIDI 2 APIs. It provides many back-ends: Pipewire, ALSA RawMidi and Sequencer, JACK on all platforms, and is tailored towards enabling application authors to ship MIDI support as easily as possible while still enabling powerful configuration and customization options to tailor the library to one's needs.