1. A method for plotting a graph using a markup language, comprising the steps of: receiving a request to generate a display of a graph comprising nodes connected by links, wherein the request identifies a first focus entity; retrieving, from a data source, first graph information describing the first focus entity and first nodes and links that are connected to the first focus entity; creating a first markup language document that contains the first graph information and which, when rendered in a display, causes plotting the first focus entity and first nodes and links that are connected to the first focus entity; receiving a request to change the display to focus on a second focus entity; retrieving second graph information describing only second nodes and links that are connected to the second focus entity, without repeating retrieving the first graph information; creating a second markup language document that contains only the second graph information and which causes, when only the second markup language document is rendered in the display, plotting both the first focus entity and the second focus entity without repeated rendering of the first markup language document.