SomniatorSound has created free virtual instruments through the Pianobook project. You can check them out here. All instruments are available for free and require Full Kontakt 5 or newer. You can also just get the samples through the site and use them without a sampler.
Unipiano swarm
A swarming piano from an university lobby with special effects and 2 microphone positions. 3 velocity layers and a few different patches.