Obsidian

Obsidian stores notes as plain Markdown files in a folder on your computer, and lets you link them, see the connections in a graph view, search all content and extend the program with hundreds of community plugins. Engineers use it as a personal or team knowledge base for project notes, design decisions, summaries of standards and lessons learned. The files stay with the user and open in any text editor. Limitation: the program is closed source, and syncing between devices through Obsidian Sync and publishing to a website are paid services.