An overview of some things you do with a Guitar to MIDI converter (like the Axon AX100, or Roland GI20 or GR33), Native Instruments' Kontakt and Gtak. This video shows Gtak4 in Kontakt4, but later versions of Gtak do exactly the same thing.
How to use String and Fret Splitting.
How to control Kontakt's Keyswitched instruments.
How to use Kontakt's Dynamic Keyswitched instruments with Gtak.
How to use Kontakt's drum machines with Gtak.
How to use Gtak to switch instruments by playing notes on your fretboard.
Here's how Gtak works with a MIDI pedal board to let you switch between instruments (in this case 17 different instruments) without you having to take your hands off your guitar.