NIH-XPLOR
From NMR Wiki
Xplor is a great piece of software that allows to calculate structures conforming experimental NMR restraints such as NOE, RDC, scalar couplings, etc.
XPLOR system is complex and hard to learn from scratch, so a good tutorial would be very desirable. There are many tools that manipulate XPLOR restraint tables. Links to them should be posted here as well.
Official NIH-XPLOR Documentation Site
References
Schwieters, C.D., Kuszewski, J.J., Tjandra, N., Marius Clore, G.. The Xplor-NIH NMR molecular structure determination package
