hnb is described as 'hierarchical notebook(hnb) is a curses program to structure many kinds of data in one place, for example addresses, to-do lists, ideas, book reviews or to store snippets of brainstorming. Writing structured documents and speech outlines' and is an app in the Office & Productivity category. There are four alternatives to hnb for a variety of platforms, including Mac, Windows, iPad, iPhone and Linux. The best alternative is Org mode, which is both free and Open Source. Other great apps like hnb are OmniOutliner (Paid), Zavala (Free, Open Source) and Dashword (Free).
OmniOutliner is a start-to-finish writing app. Perfect for collecting information, outlining Big Ideas, adding structure to any sort of writing, and much more. From grocery lists to email drafts to long-form composition.
Dashword is by far the most convenient and user-friendly tool for creating any semantic network, be it your business idea, an abstract of a lecture on computer science, a script for a movie or a recipe for your favorite dish.