D2 is a diagram scripting language that turns text to diagrams. It stands for Declarative Diagramming. Declarative, as in, you describe what you want diagrammed, it generates the image. For example, download the CLI, create a file named input.d2, copy paste the following, run this command, and you get the image below. NETWORKUSERAPI SERVERLOGSCELL TOWERONLINE PORTALDATA PROCESSORSATELLITESTRANSMIT