The Puremagnetik library isn’t just for Kontakt. They say it comes with Ableton Live and Logic Pro versions, too.
There’s also a free option currently in development. It’s called Chordian and is available only in SFZ format for the free Sforzando sampler. It’s a very different layout, a little awkward for playing in real time, but it comes with a second version called Chordial (note the L) that has some changes I suggested to make it easier to play the chords and harp (strums) without a full 88-key controller. Currently, Chordian/Chordial only has one-shot samples of the kick, snare, and hi-hat — no rhythms.