Obsidian
Obsidian is a powerful, local-first knowledge management and note-taking application that uses plain text Markdown files stored in a folder (vault) on your device. It emphasizes linking notes together to create a personal knowledge graph, enabling non-linear thinking and discovery through bidirectional connections. The tool is highly extensible via community plugins and themes, allowing users to customize their workflow for writing, research, project management, or personal knowledge bases.
Developers should learn Obsidian when they need a flexible, offline-capable system for organizing technical documentation, code snippets, project notes, or learning resources, as it supports version control integration (e.g., with Git) and plain text files that are easy to back up. It's particularly useful for building interconnected knowledge bases, such as for software architecture diagrams, API documentation, or personal study notes, where linking ideas enhances understanding and recall. The plugin ecosystem also allows for task management, diagramming, and code syntax highlighting, making it a versatile tool for developer workflows.