VSTi Host is an application that allows a VST instrument plugin (VSTi) to be used as a standalone software synthesizer, without the use of a bulky host environment (like Cubase, Logic, etc). It's perfect if you have an extra Mac that you'd love to put to use as a virtual synthesizer. It also allows sequencers that don't natively support VST instruments to now use them.
Changes to version 2.0 include the ability to use up to two VST effects in addition to the VST instrument in the audio chain, as well as an enhanced user interface.
VSTi Host is compatible with VSTi plugins from Steinberg, Native Instruments, Waldorf, and a large number of 3rd party commercial, shareware, and freeware authors.
The 2.0 version is $14.99 and may be purchased online.