VSamp is a software sample player for the Mac. It comprises: a program for creating and playing virtual instruments; a VST plugin for playing VSamp instruments from within a VST sequencer; and an AudioUnits plugin for playing VSamp instruments from within an AudioUnits sequencer.

Features:

• Up to 64 stereo sample playback = 128 voice polyphony.
• 32-bit output (VSamp application under Mac OS 7, 8 or 9 limited to 16-bit).
• Up to 192 kHz output (VSamp application under Mac OS 7, 8 or 9 limited to 48 kHz).
• Load samples into RAM for higher performance or stream from disk for lower RAM usage.
• 128 resonant lowpass filters with realtime MIDI control and modulation.
• LFO to modulate pitch and filters
• 5-stage AHDSR envelope configurable for each sample.
• Compatible with sequencers running MacOS X MIDI services, OMS and FreeMIDI.
• Compatibility with major soundfile formats including AIFF, WAVE and SDII.
• Import SoundFont2 and SampleCell 2.x samples and instrument keymaps.

More information available here.