Folio is a document-based personal computing environment. It is a functional prototype for the ideas explored in the architecture document The Document is the Computer.

In Folio, common computing tasks — calendar management, email, task tracking, note-taking, and even Python computation — all live within a single, unified text document. This approach collapses the boundaries between different applications, treating information as a continuous, structured text stream.

Folio explores how programming languages, tools, and interfaces shape the way people think and work.