Mac OS X Softwares to Infinite hierarchical depth

MyTetra is a versatile, cross-platform information manager designed for collecting, organizing, and managing various types of data. It excels as a portable note-taking application, personal information manager, and notebook, offering a robust outliner and rich text editing capabilities.

Transpose was a versatile workspace designed for individuals and teams, combining elements of note-taking, project management, CRM, and data organization into a single, flexible platform. It empowered users to structure information and collaborate efficiently.

Org-mode is a powerful and flexible mode for GNU Emacs, designed for note-taking, project planning, to-do list management, and authoring documents. It utilizes simple plain text files with intuitive markup.

Producteev is a robust task management software designed for teams to collaborate effectively and streamline workflows. It offers a centralized platform for organizing tasks, managing projects, and tracking progress, catering to various team sizes and complexities.

KeepNote is a versatile note-taking application designed for organizing information in a hierarchical structure. Available on Windows, Linux, and macOS X, it features robust organization tools, including a tree-like outline, wiki-like linking, and support for embedded files and images. Although discontinued, its local storage and rich features make it a compelling tool for detailed note-taking and research.

wikidPad is a free and open-source wiki-like notebook application that allows you to store your thoughts, notes, and snippets of information in a highly organized and cross-referenced manner. Its strength lies in the effortless creation of links between pages, making it easy to navigate and connect related ideas.

Leanote is a versatile self-hosted note-taking application that blends rich text editing with Markdown support. It offers seamless synchronization across multiple devices and features built-in blog publishing capabilities, making it a powerful tool for both personal information management and content creation.