Evernote is a note taking app and productivity tool for capturing, organizing, and prioritizing ideas, projects, and to-do lists using AI features.

Obsidian is a free and flexible knowledge base app for private thoughts, using local Markdown files and featuring thousands of plugins for customization.

Roam Research is a networked thought and note-taking tool that combines the simplicity of bulleted lists with the power of a graph database for idea connection.

Logseq is an open-source, privacy-first knowledge base and outliner for personal knowledge management and note-taking.

Reflect is a beautifully minimalist, end-to-end encrypted note-taking app designed for networked thought and enhanced by native GPT-4 AI integration.

Curtis McHale is a business coach and blogger focused on personal knowledge management, productivity, and technology.

Elephas is a Mac-native AI knowledge assistant that lets users search, summarize, and reason over their personal documents and notes (Second Brain).

Sébastien Dubois offers simple, proven systems and courses to help knowledge workers overcome information overload, master personal organization, and build effective LifeOS/PKM systems.

Elizabeth Butler MD is a productivity and personal knowledge management service for professionals and is used by busy individuals.

PolyInnovator is the central hub for Dustin Miller's works on polymathy, knowledge management (PIOS), content creation, and self-development, offering content and premium memberships.

Tools For Thought is a community for emerging tools for thought, focused on personal knowledge management and global cozyweb.