  Very-high-energy astronomy studies the Universe at energies between 30 GeV
and 100 TeV. The past decade has seen enormous progress in this field. There
are now at least seven known sources of VHE photons. By studying these objects
in the VHE regime one can begin to understand the environments surrounding
these objects, and how particle acceleration is realized in nature. In addition
the photon beams from the extragalactic gamma-ray sources can be used to study
the electromagnetic fields in the intervening space. This recent progress can
be traced to the development of a new class of detector with the ability to
differentiate between air showers produced by gamma rays and those produced by
the much more numerous hadronic cosmic-ray background. Much more sensitive
instruments are currently in the design phase and two new types of instruments
are beginning to take data. In this paper we will discuss the physics of these
sources and describe the existing and planned detectors.
