For years, developers using Literate Programming faced a tough choice. Tools like org-mode offered immense power but trapped users inside the Emacs ecosystem. Sharing work with colleagues on different editors like VS Code became a logistical nightmare, creating frustrating vendor lock-in.

This is the barrier CUE aims to dismantle. Originally known for validating YAML and generating JSON, CUE now steps into the documentation arena. It solves the classic "Copy-Paste Tribute" problem, where documentation drifts from the actual source code.

By treating documents as build targets, CUE ensures your tutorials always match the working code. It stitches code snippets together programmatically, validating that pieces fit before the file ever exists. The magic happens with the `cue cmd` engine, which requires specific `_tool.cue` filenames to execute tasks.

This turns static text into a living program. CUE can even wrap external CLI tools to render diagrams or compile Haskell on the fly. If a code snippet fails, the entire document build breaks, effectively turning writing into a rigorous CI/CD pipeline.