Hypercube is an exceptionally capable, compact and well-domented package for analysis and display of multi/hyper-spectral data. Appears to cover all "Multi-Spec" capabilities, but handles R*4 and other data types along with many more options for classification, etc. Operation is somewhat idiosyncratic, but no worse than ENVI.
Some bugs remain in data I/O in Mac version, but overall still very useful.