Phase-space methods can be traced back to early contributions in classical geometrical optics, yet it is only recently that scientists and engineers began to systematically explore the use of phase-space representations for analyzing and synthesizing optical signals. This seminal collection of 70 papers dated from 1932 through 2004 describes the spatial properties of optical signals in terms of phase-space in the classical optical fields, and sketches some of the many interesting applications of phase-space methods.