We review the current state of observational work on the formation of brown
dwarfs, focusing on their initial mass function, velocity and spatial
distributions at birth, multiplicity, accretion, and circumstellar disks. The
available measurements of these various properties are consistent with a common
formation mechanism for brown dwarfs and stars. In particular, the existence of
widely separated binary brown dwarfs and a probable isolated proto-brown dwarf
indicate that some substellar objects are able to form in the same manner as
stars through unperturbed cloud fragmentation. Additional mechanisms such as
ejection and photoevaporation may play a role in the birth of some brown
dwarfs, but there is no observational evidence to date to suggest that they are
the key elements that make it possible for substellar bodies to form.Comment: Protostars and Planets V, in pres