VCV is an open-source virtual modular synthesizer system by Andrew Belt, in collaboration with Grayscale. Powering the VCV modules is VCV Rack, a standalone software in which you can add modules, connect cables, edit parameters, and save/load patches.
VCV is designed to be used as a complete DAW for creating modular synthesizer compositions or as an extension of hardware modular systems.
Create generative patches with your mouse, perform with your MIDI keyboard controller, or connect it to your favorite DAW using the Rack Bridge VST/AU plugin (coming soon).
In Rack, control voltages and audio signals are equivalent, so you can modulate parameters with sonic-range VCOs to create customizable FM synths or chaotic wave-shaping oscillators.
If you already own a modular synthesizer, you can enhance your setup with an audio interface supporting CV signals (see  ) or a CV-MIDI-CV interface module with Rack’s CV Interface (coming soon).
Version 0.3.1 of the VCV Rack application is available for Windows 64-bit, macOS 10.7+ and Linux 64-bit. The download includes the Fundamental plugin pack with 8 high quality analog-modeling sound generators, processors, and utilities.
Registered users (free) can also add modules from the Audible Instruments range, based on the Mutable Instruments Eurorack modules, the E-Series plugin that features a port of Synthesis Technology’s E340 Cloud Generator, and Befaco’s EvenVCO, A*B+C, Spring Reverb, Mixer, Slew Limiter, and Dual Attenuverter modules.
More modules are coming soon.
More information: VCV Rack