Runmd executes Markdown files as executable scripts. It parses Markdown, extracting fenced code blocks. These blocks, identified by language tags, are then executed using the appropriate interpreter. Shell scripts, JavaScript, Python, and other languages are supported. It simplifies documentation by automatically verifying example code snippets during development. Runmd supports various options to control execution, making it a versatile tool for creating runnable documentation and testing code directly from Markdown documents.