A Lightweight Front-End Framework: UIkit
UIkit is a front-end framework, built by YOOtheme, for creating cross-browser and responsive layouts faster.
The components included cover pretty much everything: buttons, tables, tabs, forms, modals, tooltips and much more.
Everything is very-well documented with examples and a web-based customizer exists for creating new themes (there are already 3 ready-to-choose themes).
Compatibility: All Modern Browsers