13. A computer program product for displaying related content on a user interface, the computer program product comprising a computer readable storage medium having program code embodied therewith, the program code readable and executable by a processor to perform a method comprising: analyzing an initial electronic document to identify a first mention in the initial electronic document; generating a first mention descriptor of the first mention in the initial electronic document according to a context of the initial electronic document; appending the first mention descriptor to the initial electronic document; mapping the first mention descriptor from the initial electronic document to a disambiguation identifier from a knowledge base that contains a version of the first mention, wherein the disambiguation identifier is an entity within the knowledge base; associating the disambiguation identifier with the initial electronic document; locating the disambiguation identifier on an entity metadata visualization panel, wherein the disambiguation identifier was appended to the entity metadata visualization panel after mapping the entity metadata visualization panel to the disambiguation identifier from the knowledge base, and wherein the entity metadata visualization panel was mapped to the disambiguation identifier by mapping a second mention descriptor for a second mention in the entity metadata visualization panel to the disambiguation identifier; retrieving the entity metadata visualization panel; and displaying, on the user interface, the entity metadata visualization panel as related content that is related to the first mention in the initial electronic document.
13. A computer program product for displaying related content on a user interface, the computer program product comprising a computer readable storage medium having program code embodied therewith, the program code readable and executable by a processor to perform a method comprising: analyzing an initial electronic document to identify a first mention in the initial electronic document; generating a first mention descriptor of the first mention in the initial electronic document according to a context of the initial electronic document; appending the first mention descriptor to the initial electronic document; mapping the first mention descriptor from the initial electronic document to a disambiguation identifier from a knowledge base that contains a version of the first mention, wherein the disambiguation identifier is an entity within the knowledge base; associating the disambiguation identifier with the initial electronic document; locating the disambiguation identifier on an entity metadata visualization panel, wherein the disambiguation identifier was appended to the entity metadata visualization panel after mapping the entity metadata visualization panel to the disambiguation identifier from the knowledge base, and wherein the entity metadata visualization panel was mapped to the disambiguation identifier by mapping a second mention descriptor for a second mention in the entity metadata visualization panel to the disambiguation identifier; retrieving the entity metadata visualization panel; and displaying, on the user interface, the entity metadata visualization panel as related content that is related to the first mention in the initial electronic document. 17. The computer program product of claim 13 , wherein the method further comprises: performing a sentiment analysis on the initial electronic document, wherein the sentiment analysis identifies an emotion of a first author of the initial electronic document; performing a sentiment analysis on the entity metadata visualization panel, wherein the sentiment analysis identifies an emotion of a second author of the entity metadata visualization panel; generating a trending graph of the emotion of the first author and the emotion of the second author; and displaying, on the user interface, the trending graph.