Slim defaults to ugly-mode: https://github.com/stonean/slim/blob/ae14457c596c963144810ced65ac9c275498bffd/lib/slim/engine.rb#L8 https://github.com/stonean/slim/

Slim defaults to ugly-mode: https://github.com/stonean/slim/blob/ae14457c596c963144810ced65ac9c275498bffd/lib/slim/engine.rb#L8 https://github.com/stonean/slim/blob/ae14457c596c963144810ce... Haml uses pretty-mode in development and ugly-mode in production.