Zampler//RX is a freeware workstation plugin that loads SFZ + REX/RX2 files, based on Synapse Audios Dune synthesizer. It features an arpeggiator, mod matrix, 3 LFOs, 3 envelopes, multi filter, and an effects section.
The update brings 64-bit support for Mac OS X, a new skin and new sound bank. Download for free at www.zampler.de (Windows VST, OS X VST + AU, 32/64bit)
The new sound bank is called Black Venom. It includes 750 MB of sounds and can be download at www.zampler.de/upload/Zampler-Black-Venom
More sounds can be found at www.zamplersounds.com. A steadily growing source of sound banks for Zampler//RX.