... is a pluggin and a library which does time stretching/pitch shifting.
After listening to some examples they provide, I feel like it sounds better than more famous engines, like Elastique Audio.

http://breakfastquay.com/rubberband/examples.html

We are thinking in implementing in our host but I don't see much feedback on the web and not at all on KVR. Is there something wrong with it ? Do you have an idea of why it's not more famous ? Anyone has used it before ?

Never heard of it before this. First time.

Not sure why it's not popular, cause indeed from what I've heard in your audio examples it sounds quite nice and buttery smooth. I know lot of people don't like stand alone softwares and prefer having their tools as a plugin format usuable in their DAW. That might be one of the reaons...

That's an interesting point ! As I want to integrate it into the DAW we are developping, that shoudn't be a problem. My only concern is the sound quality, and I'm glad that, you think it's good too . Have to make more tests with different material, and maybe more extreme settings

It can't be used in closed source software without paying. I suppose developers of closed source commercial hosts have decided the money is better spent elsewhere, for whatever reason. (Companies like zplane and Izotope might offer better support etc when licensing their DSP technologies...)

It makes sense, but IMHO, what matters to the end user, buying closed source software, is price and sound quality. The price of this library seems to be cheaper than some better known alternatives (Izotope technology, Dirac, and Zplane) from what I heard. The sound quality on the other hand seems to be as good, if not better, so I think I'll give it a go.

Thanks guys for your input ! I'm glad that I'm not the only one who finds this library very decent sounding.

Cheers,
D.

Sounds quite good to me. Better than Ableton Live's built-in engine.
I never use anything besides Ableton Live for time stretching/pitch shifting just because it's easier to use something that is already built-in. And the results are satisfactory enough to keep using it.

I'm pretty sure that if you're going to use this engine in your DAW, it'll be an advantage (unless better engines appear).