The NOT has a long tradition in the follow-up of gamma-ray bursts, starting with observations of the very first afterglow back in 1997. Focus has been both on the physics of these events and their use as probes of the distant universe. Twenty-five years later, the NOT has become a major worldwide contributor to this field. Starting in 2017, the parallel branch of gravitational wave sources electromagnetic follow-up has also sprouted. This presentation reviews past seminal NOT contributions and highlights new science goals which can be tackled using the forthcoming NTE, whose design has been optimized for transient sources.