Mikko Maducdoc unviels a free guitar strummer VSTi for Windows called Lemonstrum. It plays any chord and strums them with the correct fret positions to give you a realistic acoustic rhythm. This is a great freeware for songwriters, arrangers, and musicians!
"Its simplicity and ease of use gets the clutter out of your way so you can focus more on the mix and forget about the mics, cables, and tuning of a real guitar." Link