# Local Development `markdown` files are rendered into HTML dynamically based on the URL that is requested. ## Create a new site `coltrane create` creates the folder structure for a new site. ```{note} More details about the `create` options and the files that are generated are in [CLI](cli.md#generated-files). ``` ## Development server `coltrane play` serves the content for local development. ```{warning} `coltrane play` is fine for development, but should never be used in production. ```