The free VSTShell host software has been updated to version 3.76.
An introduction to VSTShell v.3.76, showing the new arpeggiator features etc.
VSTShell is a host for VST & Audiounit instruments and FX (up to 4 instruments and FX), with a built in arpeggiator and sequencer, which can be used as a standalone host or to play/record into Pro Tools (or whatever) using Rewire.
VSTShell is currently available to download for Mac at no cost.
More information: VSTHell