It is straightforward to use Storyspace’s Map view for graphical layouts such as a timeline.
Eastgate
Guard links, only followed when conditions are met, allow us to structure the reading of a non-fiction book.
Creating you first hypertext in Storyspace 3: from linear to the more complex using basic and text links.
Born in the same year as HyperCard, this is the most sophisticated authoring environment for true hypertext. It is now available for OS X El Capitan.
The Eclectic Light Company 