3D is a new type of a highly sensitive near-infrared integral field spectrometer developed at MPE. It has been designed to multiplex spectral as well as spatial information thus obtaining a full data cube in a single integration. At a spectral resolution between 1000 and 2000 and a field of view of 16 by 16 pixels, optimized for subarcsecond spatial resolution imaging spectroscopy, it has a much higher efficiency compared to conventional astronomical techniques. Combining the advantages of imaging and spectroscopy increases the observing efficiency on small objects by such a large factor over existing grating or Fabry-Perot spectrometers that subarcsecond near-IR spectroscopy on faint Seyferts, starbursts, quasars or distant galaxies clusters becomes feasible for the first time on 4m class telescopes. Outfitting one of the upcoming 8-10 m class telescopes with a 3D type instrument will provide a powerful tool for diffraction-limited integral field spectroscopic research in particular on faint highly redshifted galaxies in the early universe. The basic design of 3D as well as recent results and future plans are presented.