Since the discovery of the first brown dwarfs, Teide 1 and Gl 229B in 1995, several hundreds of substellar objects have been discovered. During these fifteen years, the field of brown dwarfs has experimented a great development, only comparable to that carried out in the strongly related field of extrasolar planets. Substellar objects, on the contrary to stars, do not burn hydrogen in their interior, and this determines that their physical properties are very different. At the early stages, they contract, then their interior became degenerated, and later they evolve toward cooler temperatures when age. In this paper, I will review the most relevant results in the field of brown dwarfs and planetary-mass objects, with special interest in those that have taken place during last years. In particular, I will discuss the implications of recent works in the substellar mass function and the discovery of planetary-mass companions. Next, I will review the current knowledge of the physical properties and the evolution of substellar objects, acquired from the recent measurements of dynamical masses of brown dwarf binaries, transits around stellar primaries, and eclipsing brown dwarf binaries. Finally, I will discuss future perspective of the substellar field during the next years, in particular for the discovery of the coolest substellar objects in the solar vicinity and the future search for extrasolar planets around very low-mass stars and brown dwarfs.