AsciiDoc is a lightweight markup language used for writing documentation and articles in a plain text format. It allows users to create formatted documents using simple syntax, making it easy to read and write. AsciiDoc can be converted into various output formats, such as HTML, PDF, and EPUB, which makes it versatile for different publishing needs. Developed by DocBook creator Dan Allen, AsciiDoc is designed to be user-friendly while still providing powerful features for technical writing. It supports elements like headings, lists, tables, and images, enabling authors to structure their content effectively without complex formatting tools.