Quote Originally Posted by GrumblingHive View Post
Like, draw the first line at any old angle, the next line is at a right angle to the first, the next line is at a right angle to the second, etc. etc. etc. etc.
Just FYI, the third line in your example will be parallel to the first, the fourth will be parallel to your second, etc.
So that if you have a situation where most lines are either parallel or perpendicular to each other, it might be easier to draw them horizontal and vertical and rotate the entire drawing after all the lines are drawn.

If each small group of lines has its own orientation (like buildings in a village) then software with a simple select-and-rotate or draw-perpendicular command would probably be better.

Good luck on the software search.
[I use Autocad, but with a thousand dollar price and hundred hour learning curve ... I don't really recommend it for your needs.]