pjnmr 3.0 for Mac can be downloaded from our website for free. This free software for Mac OS X was originally designed by University of Alberta.
From the developer:
Successor to MacNMR (1984). Written by Paul Jean Letourneau as a joint project with NANUC (Canadian National NMR Centre) and PENCE (Protein Engineering Centres of Excellence) in java (PureJavaNMR, PJNMR) to run on multiple platforms. Includes vector graphic display of up to 3 coupled spins including up to three different nuclei and the effect of gradients.