MSoundFactory may well be the most powerful instrument out there. It's modular, so you can have any number of oscillators, filters, samplers etc. you want. It features per-voice and global modulation, full MPE support, the best sounding oscillators on the market, a fully modular effects engine.
A beta version is available for purchase with an introductory price
MSoundFactory will most likely be a never-ending project. We are probably not going to make any further instruments, instead we are going to implement further modules and features into the mighty MSoundFactory. MSoundFactory currently comes with many presets converted from MPowerSynth and several fully featured instruments, but it's far from being "ready". However it can already be used by creative minds looking for an extremely powerful instrument. The only necessary module needed to be added to the first official release is a sampler, so please stay in tune.