Sass (Syntactically Awesome Stylesheets) is a stylesheet language initially designed by Hampton Catlin and developed by Natalie Weizenbaum. After its initial versions, Weizenbaum and Chris Eppstein continued to extend Sass with SassScript, a simple scripting language used in Sass files.Sass is a scripting language that is interpreted into Cascading Style Sheets (CSS). SassScript is the scripting language itself. Sass consists of two syntaxes.