In the article, Arnab Roy Chowdhury explores 18 free CSS3 resources that have significantly impacted web design by enabling developers to create responsive, lightweight, and visually appealing websites with less code. These resources include popular frameworks like Bootstrap, Foundation, and Bulma, which offer extensive UI components and responsive grid systems, as well as innovative tools like LESS and SCSS that streamline coding processes. Smaller frameworks such as Skeleton and Mini.css provide efficient solutions for creating fast-loading and mobile-friendly layouts, while tools like Atomic Bulldog Grid and Simple Grid CSS offer specialized functionalities for specific design needs. Chowdhury emphasizes the importance of these tools in modern web development and encourages developers to experiment with and combine different frameworks to keep up with evolving design trends.