  A comparison of the most popular techniques for 3D spectroscopy is presented
in a way which should hopefully be useful for astronomers intending to use
these techniques. Integral field spectroscopy, slitless spectroscopy, tunable
imaging filters, imaging Fourier transform spectroscopy, and energy-resolving
detectors are included in their different implementation. Their relative
advantages and disadvantages are discussed in view of the possible scientific
application.
