Freeware: Visio

Visio Occam 1.1 Visio stencil for Occam. The template provides a blank drawing canvas and defines the way connections flow on a drawing. All the symbols have connection points at suitable locations.

DiagramDraw 1.01 Diagram Draw provides you with a 100% professional toolkit for creating various diagrams and projects, highly competitive in any aspect with similar programs, even in comparison with MS Visio. The program is high-quality and free to anyone

GStarICAD 2007-11-1 GStarICAD is the geniune CAD drawing software based on IntelliCAD,and it is 99% idential to AutoCAD but with a competitive price.GStarICAD offers a 30days free tryout after free download this software