Lex is a collaborative writing tool that integrates an AI editor to assist with drafting, revising, and refining written content. It offers a clean, minimal interface designed to help writers focus. Key features include AI feedback for improving drafts, on-the-fly rewriting, title suggestions, and context-aware commands to generate ideas or find the right word. Collaboration is supported through real-time editing, comments, and version history. Documents can be shared as read-only links for publishing. Lex is used by over 300,000 writers for a variety of tasks, from note-taking and academic papers to marketing copy and novel writing. The AI acts as a writing partner, helping users overcome writer's block and enhance their work without disrupting the creative process.