technical developments at long wavelengths, including infrared array detectors, millimeter-wavelength aperture synthesis, and self-calibration and refmed deconvolution algorithms in aperture synthesis radio astronomy. The center of the Galaxy is also accessible to X and gamma-ray observers, and progress at high energies has been steady, especially as imaging capabilities are being realized at X-ray wavelengths. However, one might expect that the revolution in the high­ energy domain is still ahead of us, as instruments with larger collecting areas and improved spatial resolution are now being developed. The youth of this subject is evidenced by the relatively small number of meetings that have been devoted to it.