  The phase-space formulation of quantum mechanics has recently seen increased
use in testing quantum technologies, including metho ds of tomography for state
verification and device validation. Here, an overview of quantum mechanics in
phase space is presented. The formulation to generate a generalized phase-space
function for any arbitrary quantum system is shown, such as the Wigner and Weyl
functions along with the asso ciated Q and P functions. Examples of how these
different formulations have b een used in quantum technologies are provided,
with a focus on discrete quantum systems, qubits in particular. Also provided
are some results that, to the authors' knowledge, have not been published
elsewhere. These results provide insight into the relation between different
representations of phase space and how the phase-space representation is a
powerful tool in understanding quantum information and quantum technologies.
