FluidSynth is a real-time software synthesizer that generates audio by reading and handling MIDI events from MIDI input devices by using a SoundFont. FluidSynth can also play MIDI files. FluidSynth itself does not have a graphical user interface, but due to its powerful API several applications utilize it and it has even found its way onto embedded systems and is used in some mobile apps.

• Cross platform support (Linux, macOS and Windows to name a few)
• SoundFont 2 support
• SoundFont 3 support (vorbis-compressed SF2)
• Realtime effect control using SoundFont 2.01 modulators
• Limited support for Downloadable Sounds (DLS) Level 1 & 2
• Playback of MIDI files
• Shared library which can be used in other programs
• Built in command line shell