Obsidian

Obsidian is a powerful knowledge base that works on top of a local folder of plain text files. It's a second brain, for you, forever. Your data is stored privately on your device, ensuring you have access even when offline and that no one else can read your notes. By using open, non-proprietary file formats like Markdown, you guarantee that your knowledge will last for the long term.

The true power lies in connecting your thoughts. Create a dense network of knowledge using bi-directional links and visualize the relationships between your notes with an interactive graph view. This helps you discover hidden patterns and generate new ideas. The experience is highly customizable, with hundreds of community plugins and themes available to shape the tool to your unique way of thinking. Optional add-on services allow you to sync notes with end-to-end encryption or publish your notes as a website.