# Cecil > Cecil is a command-line PHP application that merges Markdown pages, medias and Twig templates to generate a static website. ## Documentation - [Quick Start](https://cecil.vercel.app/documentation/quick-start.md): Create a new website and preview it locally. - [Content](https://cecil.vercel.app/documentation/content.md): Create content and organize it. - [Templates](https://cecil.vercel.app/documentation/templates.md): Working with layouts, templates and components. - [Configuration](https://cecil.vercel.app/documentation/configuration.md): Configure your website. - [Commands](https://cecil.vercel.app/documentation/commands.md): List of available commands. - [Deploy](https://cecil.vercel.app/documentation/deploy.md): Deploy (publish) your website. - [Extend](https://cecil.vercel.app/documentation/extend.md): Extend Cecil. - [Library](https://cecil.vercel.app/documentation/library.md): Use Cecil as a PHP library. - [Architecture](https://cecil.vercel.app/documentation/architecture.md): Cecil architecture. ## How to? - [Apply SEO features in templates](https://cecil.vercel.app/how-to/templates-metatags.md): Add Cecil SEO features to templates with the metatags partial. - [Optimize images in Markdown](https://cecil.vercel.app/how-to/markdown-performance-images.md): Optimize Markdown images in Cecil with responsive sizes, formats, and lazy loading. - [Generate multiple formats of an image in templates](https://cecil.vercel.app/how-to/templates-image-formats.md): Generate AVIF and WebP image formats in Cecil templates. - [Render responsive images in templates](https://cecil.vercel.app/how-to/templates-responsive-images.md): Render responsive images in Cecil templates with the html function.