15. A computer for providing information about content of an electronic book (ebook) that is displayed at a client device, the computer comprising: a processor; and a non-transitory computer-readable storage medium storing computer program instructions executable by the processor, the instructions comprising instructions for: determining a set of layers available for use with the ebook displayed at the client device, one or more layers of the set of layers providing one or more types of information associated with one or more types of ebook content at one or more positions in the ebook; transmitting, to the client device, a list identifying the available layers in the set, the client device using the list for: identifying activated ebook content activated by the user and a position range of the activated ebook content; determining, from the list of available layers, one or more matching layers that can be used to interact with the activated ebook content according to a type of the activated ebook content; and launching a layer from the one or more matching layers with respect to the activated content; receiving, from the client device, the position range and an identification of the launched layer; translating the received position range to a translated position range associated with a translated version of the ebook different from a client version of the ebook displayed at the client device; and identifying the layer information associated with the ebook content identified by the translated position range, the layer information identified specific to the launched layer; and transmitting, to the client device, the identified layer information for display in conjunction with the activated ebook content identified by the received position range.
18. The computer of claim 15 , wherein the layer that was launched by the client device includes a named entity layer, wherein identifying the layer information comprises: identifying one or more named entities referenced by the activated ebook content identified by the translated position range; and obtaining entity data for the one or more named entities referenced by the activated ebook content identified by the received position range, and wherein the identified layer information includes the obtained entity data for the one or more named entities.