Free Apps with 'Hierarchical Structure' feature for Windows

Obsidian is a note-taking app that lets you create a personal knowledge graph with ease. It is designed for non-linear thinking and allows you to easily link your notes together wiki-style.

Open source note-taking app with Markdown support, to-do integration, and synchronization with cloud services like Dropbox and OneDrive.

Highly customizable browser with built-in ad and tracker blockers, Chromium compatibility, advanced tab management, cross-device sync, and strong privacy features.

Disk analysis tool with treemap views, duplicate file detection, and cleanup actions. Works offline and ad-free on Windows as an open-source project.

Privacy-focused diagramming software supporting real-time collaboration, offline mode, and cloud storage without ads or registration.

Local-first, privacy-focused notebook supporting Markdown and Org mode, offline use, encrypted backup, extensible with plugins, and more.

Streamline teamwork with real-time collaboration, drag-and-drop content organization, and visual simplicity across notes, tasks, wikis, and databases.

Notesnook is a simple and cross-platform private notes app that keeps your notes organized and synced on your phone, tablet and computer. Take notes, capture ideas, create to-do lists, keep a journal, write your assignments and manage projects, we have got you covered.

Comprehensive writing tool for notes, citations, and drafting with privacy-first features and multi-language support, perfect for diverse writing tasks.

Microsoft OneNote, part of the Microsoft 365 Copilot, is a digital notebook application that gives people one place to gather notes and information. It also offers shared notebooks, syncing between multiple computers and devices via Windows...

Modern Windows file manager with tabbed browsing, dual-pane view, column navigation, integrated archive tools, file tagging, QuickLook support, and appearance customization.

Emphasizes privacy with end-to-end encryption, Proton Drive safely stores, synchronizes, and shares files across devices via web and mobile applications.

Zim brings the concept of a wiki to your desktop. Store information, link pages and edit with WYSISYG markup or directly typing some lightweight markup syntax and see it previewed as-you-type. Creating a new page is easy by either clicking on the "Create new note"...

Geany is a powerful, stable and lightweight programmer's text editor that provides tons of useful features without bogging down your workflow.

Open-source, privacy-focused workspace merging notes, tasks, project management, Kanban, Pomodoro timer, interactive whiteboard, and real-time collaboration.

Manages tasks across all platforms with advanced language recognition. It integrates with 60+ tools, and offers templates for various projects.

Privacy-focused, cross-platform tool for tagging, browsing and managing files or folders, with note-taking, Kanban, S3 cloud support, and web clipping.

GNU Emacs is an extensible, customizable text editor—and more. At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing. The features of GNU Emacs include:

Free, open-source note-taking with rich text, cross-platform support, syntax highlighting, embedded files, and customizable interface.

The original trilium is transfered to this repo by its owner and the app continues to develop here as stated here: https://github.com/TriliumNext/Trilium

Provides infinite text-based nested lists, real-time collaboration, tagging, file uploads, kanban boards, offline access, and seamless sync across devices.

Cross-platform mind mapping and brainstorming app with support for multiple languages, collaboration, diagram templates, cloud sync, and export options.

A "hierarchical spreadsheet" that is a great replacement for spreadsheets, mind mappers, outliners, PIMs, text editors and small databases.

Your personal note-taking haven for privacy and efficiency.

SiYuan is a desktop Markdown Block-Reference and Bidirectional-Link note-taking application. Support fine-grained block-level reference and Markdown WYSIWYG.