There are lots of free organ VSTs out there, all of which - being completely ignorant of programming - I'm pretty impressed by. LightBag (?) stands out though, not just for the degree of its authenticity (which is not fantastic, but is pretty good in parts) but for what you can do with it, as demonstrated by the excellent collection of presets. There are lots of usefull knobs and buttons to twiddle, all of which make an immediate difference to the sound, and the interface, like the sounds, is satisfying, unpretentious and appealing. There is also an excellent manual in .pdf. I've not needed customer support, though there is an email address supplied on the download page, and so far it hasn't shown any signs of instability. I think I'm going to have a lot of fun with this, and it definately comes recommended.