This topical volume reviews a comprehensive set of problems raised by the use of Gamma Ray Bursts (GRBs) as cosmological probes, as they were addressed and debated during the ISSI-Beijing workshop "Gamma Ray Bursts: A Tool to Explore the Young Universe," which took place from April 13 to 17, 2015, in Beijing. The invited authors represent both the GRB community stricto sensu and the community studying high-redshift galaxies and star formation history. The chapters of the book elucidate the connection between GRBs and the deep universe, stimulating thoughts on how to develop worldwide synergies between high-redshift GRB studies and surveys of the deep universe. Originally published in Space Science Reviews, Volume 202, Issue 1-4, December 2016