The Composite Sampler is an LV2 plugin that acts as a MIDI-controllable sampler. It is best suited for drum samples, and supports Hydrogen drum kits.
This plugin is identified in LV2 by the URI http://gabe.is-a-geek.org/composite/plugins/sampler/1. Note that this URI is just a name... you do not need to access gabe.is-a-geek.org in order to use the sampler.