All the previous section should have made clear that globular clusters can be used for a very wide variety of studies. They can constrain the star formation history of galaxies, in particular on the two or more distinct epochs of star formation in early-type galaxies. They can help explaining the building up of spiral galaxies, and the star formation in violent interactions. They can be useful to study galaxy dynamics at large galactocentric radii. And finally, they provide an accurate distance indicator, independent of Cepheids and the distance to the LMC. This makes the study of globular cluster systems one of the most versatile fields in astronomy.
Extragalactic globular cluster research experienced a boom in the early 90s with the first generation of reliable CCDs, and the first imaging from space. We can expect a continuation of the improvement of optical imaging, but more important, the field will benefit from the advancement in near-infrared imaging, and most of all, of the upcoming multi-object spectrographs on 10m telescopes. The next little revolution in this subject will come with the determination of hundreds of globular cluster abundances around a large number of galaxies. The next 5 years will be an exiting time.
Acknowledgments
First of all, I would like to thank the Astronomische Gesellschaft for awarding me the Ludwig-Bierman Price. I feel extremely honored and proud. For his constant support, I would like to thank Tom Richtler, who introduced me to the fascinating subject of globular clusters. For the most recent years, I would like to thank Jean Brodie for her collaboration and for giving me the first opportunity to use a 10m telescope to satisfy my curiosity. I am grateful to my current collaborators Thomas Puzia, Claudia Maraston, Daniel Thomas, Denis Burgarella, Veronique Buat, Sandra Chapelon, Michael Hilker, Dante Minniti, Paul Goudfrooij, Linda Schroder and many others, for helping me to keep up the flame. As usual, I would be lost without Karl Gebhardt's codes and sharp ideas. I am grateful to Klaas de Boer and Simona Zaggia for comments on various points. And last but not least, I am very thankful to Steve Zepf for a critical reading of the manuscript.