Sass vs Stylus: What are the differences?
What is Sass? Syntactically Awesome Style Sheets. Sass is an extension of CSS3, adding nested rules, variables, mixins, selector inheritance, and more. It's translated to well-formatted, standard CSS using the command line tool or a web-framework plugin.
What is Stylus? Expressive, robust, feature-rich CSS language built for nodejs. Stylus is a revolutionary new language, providing an efficient, dynamic, and expressive way to generate CSS. Supporting both an indented syntax and regular CSS style.
Sass and Stylus can be categorized as "CSS Pre-processors / Extensions" tools.
"Variables" is the primary reason why developers consider Sass over the competitors, whereas "Simple" was stated as the key factor in picking Stylus.
Sass is an open source tool with 12K GitHub stars and 1.93K GitHub forks. Here's a link to Sass's open source repository on GitHub.
According to the StackShare community, Sass has a broader approval, being mentioned in 2082 company stacks & 1445 developers stacks; compared to Stylus, which is listed in 69 company stacks and 45 developer stacks.