Noise Engineering have announced three experimental synths available as VST/AU/AAX plugins, out on public beta now. Check their site for examples of other software they've released. Here is some detail on the releases:
Sinc Vereor's intuitive and inviting controls belie the power of this lightweight synthesizer. Sinc Vereor is loosely based on their gone-but-not-forgotten module Sinc Iter. Tweak the wavemorphing/wavefolding Tone control to make sound design a breeze. All your favorite Sinc modes are here! Blend between familiar waveforms like saw, triangle, and square. Super mode adds 6 phase-offset oscillators. Use Noise mode to generate self-similar noise for percussion, effects, and more.
Virt Vereor is a powerful synthesizer based on a unique set of synthesis algorithms. Bass is a quadrature algorithm described in Bernie Hutchins' seminal series Electronotes. Sawx is a supersaw-inspired beast. Harm is an additive algorithm with spectral control and distortion of partials. Virt Vereor makes a tremendous amount of unique sounds with an immediate and usable interface.
Ruina is a creative stereo distortion plugin built on digital distortion algorithms similar toRuina Versio: no emulations here. Intuitive and fully automate-able controls make it easy to get a gentle, nuanced color, to oblitiate a signal, or to dial in anything in between. Don't feel like tweaking the parameters? Ruina comes with tons of presets to fit any need.
More information from their blog: https://www.noiseengineering.us/blog/public-beta