The document discusses HAML and SASS, template languages that aim to reduce repetition in HTML and CSS through concise syntax and the ability to nest code and include partials. It notes that HAML and SASS work best for projects with complex page structures, a build process, and view caching, and are not as well suited for projects where the production staff are new to HTML and CSS. Implementations of HAML and SASS exist for many programming languages and environments like Ruby on Rails, PHP, and JavaScript.