Respiro comes with a wide range of tones. It is very strong at reed-type sounds, but has quite a bit of range with edge-blown flutes, brassy sounds, harmonica and even bass tones. You have a fixed number of "instruments" from the developer (who releases new instruments with subsequent udpates)-- but the selection is good. And, you can create your own variations of sounds using the "Macro" controls.
As of this release the included sounds aren't organized very well, but there are user tags that allow you access a sorted list. You can also edit the response, timbre and other qualities of the sound to create your own "variants" of the original sound. It is versatile, especially with regard to controls. The mod matrix is excellent. It also has a great reverb, compressor, vibrato & tremolo, and other important expressive features that sound very musical. There is a micro-tuning feature that allows you to tune the 12 notes of equal temperament for one octave (repeating octaves).
There are very few woodwind modeling synths out there. Reaktor's Silverwood, is one example of a synth that tries to replicate a specific real woodwind instrument. Where Respiro doesn't strive to emulate a specific woodwind instrument, it is more aimed at creating a diverse set of new yet real-sounding expressive instruments.
I've really enjoyed getting to know this amazing sounding virtual wind instrument collection!.
An outstanding piece of software from a developer that oozes passion for wind synthesis from every pore in his body! Developers like Rudy need every bit of support and encouragement (financial too!) they can get if the wind playing fraternity are going to benefit from being able to move away from old technologies and immerse themselves in the fruits of superior processing power that we now have at our disposal. I'm in no way affiliated with the developer and wish there were many more like Imoxplus that strive to respond so quickly to the needs and suggestions of their followers with such enthusiasm.
I like this Respiro. The idea to combine several wind instruments to create new sounds, is great. Some of these new instruments sound really good. With a wind controller (or another MIDI controller), you have great control over many parameters. Last, but not least, the developer is a nice guy who reacts to comments and improvement-ideas (There is also a forum on the imoxplus-page).