Double-line 90° links

Could someone please point me out on how I could go about creating a

double-line link (single link but is drawen as two line running in parallel)?

And also how would I go about making links bend @ 90° ? Thank you in

advance. (=

The easiest thing to do is to define a HighlightPen that is fairly wide, and a Pen that is the same color as the background. And you can set GoLink.Orthogonal to true.
The Pipe used in InstrumentDemo is almost what you are looking for, except for the color of the Pen being gray instead of the background color. Of course you don’t need to define your own class if you just want to change the appearance–presumably you don’t need Pipe’s dealing with Flow and Rate.