Less (sometimes stylized as LESS) is a dynamic style sheet language that can be compiled into Cascading Style Sheets (CSS) and run on the client-side or server-side.Designed by Alexis Sellier, Less is influenced by Sass and has influenced the newer "SCSS" syntax of Sass, which adapted its CSS-like block formatting syntax. Less is open-source. Its first version was written in Ruby; however, in the later versions, use of Ruby has been deprecated and replaced by JavaScript.