Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
VSTHost - Hostprogram for VST-Plugins with ASIO-Support
VCV Rack - A cross-platform modular synthesizer.
Gig Performer - Gig Performer is a cross-platform audio plugin host for live music performances
Reaktor - Native Instruments Reaktor is a virtual, modular synthesis platform.
Blue Cat's PatchWork - Blue Cat's PatchWork is a universal plug-ins patchbay and multi FX that can host up to 64 VST, VST3, Audio Unit or built-in plug-ins into any Digital Audio Workstation (DAW) in a single instance, with both serial and parallel routing options.