A brief on popular css frameworks being used in modern web applications. These frameworks ease the life for front end developers by providing a convention for coding the markup. They generally provide a grid system, a set of ui components such as button, cards, etc and javascript APIs to interact with those components. All the below choices are open source.
Bootstrap
Most popular CSS framework from Twitter. Unopinionated – Doesn’t impose constraints on the look and feel. Mobile first responsive approach. Well documented and widely used. Large file size (>250k) OOTB containing the whole feature set which you may not need most of the times.
Materialize
CSS framework for Google’s material design. Opinionated – Dictates the look and feel of the website. Large collection of interesting UI components. Go for this if the design follows material design.
Semantic UI
Allows writing concise HTML with semantic vocabulary. Supports theming. Large collection of components.
Foundation
Smaller community. Large collection of widgets.