3D DOSY experiments have the potential to provide unique and valuable information, but they are underused, in part because of the lack of efficient processing software. Here, we illustrate the power of 3D DOSY and present MAGNATE, Multidimensional Analysis for the GNAT Environment, an open-source and free software package for the analysis of pulsed field gradient (PFG) 3D NMR diffusion data, distributed under the GNU General Public License. The new software makes it possible for the first time to efficiently analyze and visualize 3D diffusion (e.g., 3D HSQC−DOSY) data using both univariate (e.g., DOSY) and multivariate (e.g., OUTSCORE) methods in a userfriendly graphical interface. The software can be used either independently or as a module in the GNAT program.