RealCADD

RealCADD is a highly-precise computer-assisted design tool that contains a script system allowing you to automate repetitive drawing tasks, and a layer system that will make editing easier.

It has two drawing modes (click and drag or click and click), different 'snap' forms (cell, object end, object center, perpendicular, tangent, intersection) and a ton of drawing tools (text, text with line, rounded rectangle, ellipsis, arc, polygon, etc).

RealCADD includes ten additional line types and other arrows for drawing and measuring objects. That's all added to another ten shading patterns and ten textures.