Obsidian

Obsidian is a versatile and powerful knowledge base application designed to help users organize their thoughts, notes, and ideas. It operates on a unique principle: all your data is stored as plain text Markdown files directly on your device. This approach ensures complete data ownership, privacy, and the ability to access your information offline at any time. The core strength of Obsidian lies in its ability to create rich, interconnected networks of notes through bi-directional linking, allowing users to discover relationships and build a comprehensive personal knowledge graph. The tool goes beyond simple note-taking by offering features like an interactive graph view to visualize connections, and a 'Canvas' for freeform brainstorming and diagramming. Its extensibility is a major draw, with a vibrant community contributing thousands of plugins and themes that allow users to tailor the application to their specific workflows and preferences. While the core application is free for personal use, optional paid services like Obsidian Sync and Obsidian Publish provide cloud synchronization and web publishing capabilities, respectively.