"This project is a fork of the Android Open Source Project 'platform_external_sonivox', including a CMake based build system to be used not on Android, but on any other computer Operating System. Google licensed this work originally named Sonivox EAS (Embedded Audio Synthesis) from the company Sonic Network Inc. under the terms of the Apache License 2.0."
See also: https://sourceforge.net/projects/drumstick/files/2.7.1/ Changes in v2.7.1: Fixed ticket #45: the sonivox library dependency (for the SonivoxEAS synth backend) is optional, and easily forgotten by 3rd party packagers. The build system configuration now fails with an error message if the sonivox library is missing unless the cmake variables USE_SONIVOX and USE_PULSEAUDIO are set to OFF. Same failure with the FluidSynth backend and the variable USE_FLUIDSYNTH, and the ipMIDI Network backend and USE_NETWORK.
See also: https://repology.org/project/sonivox/versions
Changes in v2.7.0: ticket #44: removed sonivox library sources from the source tree. New option USE_SONIVOX to let the user decide to build the sonivox eas synth plugin or not.