It's crazy that SAVI host hasn't got a review yet.
This is one of the best free tools around, like a Swiss Army knife, it's perfect to quickly check out a VST instrument without the need for a DAW, or to use a VST instrument without a DAW.
Here's basically what one needs to do:
1: Download SAVI host
2: Unzip/Unrar downloaded file
3: Place unpacked "SAVI.exe" file in same folder as "X-VST.dll"
4: Rename "SAVI.exe" to exactly the same name as "X-VST.dll", in other words = "X-VST.exe"
5: Double click renamed "X-VST.exe" to start instrument
The programme got lots of features, like recording of perfomances that can be saved as wav files.
MIDI is supported, and have worked well with my interfaces. The latest version of the host allows up to 3 MIDI controllers to be connected at once, so you can for instance use your big 76 key MIDI controller for playing, and add to that a little AKAI mini for knob twiddling (via right-click MIDI learn). Both will work at the same time.
But there is even no need for a MIDI keyboard, in SAVI host one can use the regular computer keyboard as a two octave piano keyboard. This is a programme that just keeps on giving!