VCV Rack Plugin [Free]
An audio plugin of virtual Eurorack modules. A free download for VCV Rack written in C++ under an MIT licence. Downloads are in the tens of thousands and as such it’s KRT’s most popular software.
Download here by subscribing and then updating the library from within the VCV application. There is a free version of VCV available from the VCV homepage as well as a pro version with a VST adapter for integration with your music DAW. It’s a very nice experimental audio platform with many third party plugins.
The development SDK is also free, although some things like the GUI have a licence requiring you not to sell plugins based on the free GUI components. You can put forward plugins using your own graphics to sell via the VCV store.