Komodo
Komodo is a semi-modular synthesizer.
It has a vast range of self contained synth engines, Virtual Analog, Physical modelling, FM, and Bell tones (Ring mod) all routable via filters, Vector controllers, and a variety of envelopes and LFOs then on to multiple effects stages.
Each sound engine can furthermore be controlled by a combination of Keyboard, Sequencers or Arpeggiators.
Things can get crazy very quickly. Its also a very large GUI so some may struggle to fit it onto their screens. Komodo has historically not been that popular as it is a dificult beast to tame but persevere and you will be rewarded.
Visit: Komodo