By the early 1990s, several groups of scientists in the fields of neutron and X-ray science were frustrated that each of the instruments they worked with had a locally defined format for recording experimental data.
Three parallel developments led to the creation of NeXus: These scientists proposed methods to store data using a self-describing, extensible format that was already in broad use in other scientific disciplines.
Their proposals formed the basis for the current design of the NeXus standard which was developed across a series of workshops organized by Ray Osborn (ANL), attended by representatives of a range of neutron and X-ray facilities.
The way in which Base Classes are combined is then given by an Application Definition, which describes the hierarchical structure, the minimum set of required information and optional additions for a type of experiment.
The NIAC reviews any proposed amendments to the NeXus base classes and application definitions, and holds votes to ratify changes.