The Alpine Project has released three different free orchestral (brass and woodwind) instruments for NI Kontakt. Nice demo tracks are available.
“This French Horn Sample Library is based on samples from the University of Iowa Music Instrument Samples. It is very playable and simple to use. But most of all, it has a great sound. The dynamic range of the instrument is very large, due to the modeled dynamics.
This English Horn Sample Library is based on samples from the free Eddie’s English Horn Soundfont.
This Bass Clarinet library uses samples from the University of Iowa MIS.”