Physical model of a string (simulates newtonian forces in beads of a string)
Most so-called string modelling ensembles use delays (with delay time modified by pitch). This ensemble calculates the actual newtonian forces at 40 points on a virtual string for each sample.
The good news is that this gives a lot of advantages (e.g. being able to damp only parts of the string, and also being able place pickups all over the string). The bad news is that it eats a lot of resources; i get 8 voices for 75% processor time on a P4 2ghz.
Other news is that it dosn't always sound like a string:). But it does produce some interesting and rich sounds. It's it notably responsive for how you pluck/bow the string and where on the string you pluck/bow it.
It also features a feedback system that feeds the combined output back into the strings. The practical value of this is that you can play a chord and hear new harmonics form by themselves. Guitar players might notice that this is similar to plucking a string, damping it, and then still being able to hear the other 5 strings vibrate in related harmonics. The impractical value of this is that you can get loud self sustained feedbacks if you're not careful.
As a bonus, I've included a StringReverb. Instead of plucking or bowing the string, you feed a mono input to the string. It sounds more like playing a gig inside a metallic tube, however.
There's lots of room for improvement on this instrument. Feel free to experiment with it (and please send me a note if you come up with something interesting)