dia: dia (a diagram editor) dia: dia: Dia is roughly inspired by the commercial Windows program 'Visio', dia: though more geared towards informal diagrams for casual use. It can be dia: used to draw many different kinds of diagrams. It currently has dia: special objects to help draw entity relationship diagrams, UML dia: diagrams, flowcharts, network diagrams, and many other diagrams. It dia: is also possible to add support for new shapes by writing simple XML dia: files, using a subset of SVG to draw the shape. dia: dia: