  Dome A in Antarctica has been demonstrated to be the best site on earth for
optical, infrared, and terahertz astronomical observations by more and more
evidence, such as excellent free-atmosphere seeing, extremely low perceptible
water vapor, low sky background, and continuous dark time, etc. In this review
paper, we present a complete picture of the development of astronomy at Dome A
from the very beginning, review recent progress in time-domain astronomy,
demonstrate exciting results of the site testing, and address the challenges in
instrumentation. Currently proposed projects are briefly discussed.
