A few months ago, Twitter released Bootstrap, a UI framework for websites that caused such an impression that it quickly become the most followed project on Github.
But along with Bootstrap has emerged an ugly, insidious and destructive developer antipattern: embedding Bootstrap's CSS classes directly in HTML. Not just end-developers: nearly every library that implements support for Bootstrap does it.
The solution to this is so easy that its lack of popularity and diffusion makes us burn with nerd rage.
Like Sass and SCSS, Less provides mixins, meaning that if you write your stylesheets in Less rather than CSS, you can include the Bootstrap classes in your stylesheet rather than in your HTML