Drayfus is a book discovery platform that organizes reading recommendations by mood and thematic fit rather than traditional genre categories. The service enables readers to create and contribute to collections called stacks, which are small, hand-picked groups of books organized around subjective experiences or themes. Example stacks include winter horror novels where cold is a central threat, introductory science fiction reads, standalone non-Tolkien fantasy books, and crime novels that focus on motive rather than mystery. The stated purpose of the platform is to help users find books based on what they feel like reading, not the genre. The main feature of Drayfus is its stack system. Stacks are built either by individual readers or collaboratively, with users able to add books they think belong to an existing stack. Each stack presents its books in an order chosen by the creator. Users can search stacks created by others, browse thematic collections, or build their own stacks. The platform also includes an Antilibrary feature and documentation explaining what stacks are and how they work. Typical use cases include seeking reading recommendations for a specific mood or interest, exploring hand-picked thematic collections, contributing titles to community stacks, and creating original stacks around particular themes. The workflow generally involves finding a stack that matches a desired reading experience, reviewing its curated selection, and either reading the recommended books or adding further titles to the collection. Stacks can also be in progress, with some marked as still being built and open for additional contributions.