VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
VCV Rack - A cross-platform modular synthesizer.
foobar2000 - An advanced freeware audio player for the Windows platform.
Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
Winamp - Winamp is a media player that allows users to play multiple-file formats, arrange media in a varied file-management system, and play unique media with AAC encoding.
Reaktor - Native Instruments Reaktor is a virtual, modular synthesis platform.