DocFX is a .NET-based documentation generator that creates static HTML websites from Markdown, YAML metadata, .NET API comments, and REST API specifications. It features a modular architecture with a plugin system for extensibility, processing pipelines for different document types (conceptual, managed reference, REST API), and a template engine for customizable output. The system processes input files through metadata extraction, template application, and post-processing to generate documentation sites. Key components include a command-line interface (docfx.exe), build orchestration, schema-driven document validation, cross-reference resolution, and resource handling. The tool supports multiple templates (default, modern, statictoc) and output formats including HTML and PDF via Playwright rendering.