Pencil is a free and opensource tool for making diagrams and GUI prototyping that everyone can use. Top features: * Built-in stencils for diagraming and prototyping * Multi-page document with background page * Inter-page linkings! * On-screen text editing with rich-text supports * Exporting to HTML, PNG, Openoffice.org document, Word document and PDF. * Undo/redo supports * Installing user-defined