The field of fluorescence continues to steadily grow, both in its fundamental aspects and in applications in highly interdisciplinary areas including analytical, physical and organic chemistry, molecular sciences, biology, biomedicine and medical research. The 4th volume in the Springer Series on Fluorescence focuses on the fluorescence of nanosystems, polymers and supermolecules, and the development and application of fluorescent probes. Special emphasis is placed on the fluorescence of artificial and biological nanosystems, single molecule fluorescence and the luminescence of polymers, micro- and nanoparticles and nanotubes. Fluorescence microscopy and fluorescence correlation spectroscopy are covered as well. Historical aspects of this growing field and an overview of fluorescence applications are also provided.