JGo
Build custom interactive diagrams, network, workflow editors, flowcharts, or software design tools. Includes many predefined kinds of nodes, links, and basic shapes. Supports layers, scrolling, zooming, selection, drag-and-drop, clipboard, in-place editing, tooltips, grids, printing, overview window, palette. Versions for Swing and for SWT/Eclipse. Document/View/Tool architecture with many properties. Optional automatic layout and instruments.