Animate.css
This Is Responsive | Tips, Resources and Patterns for Responsive Web Design
Patterns, resources and news for creating responsive web experiences
A Selection Of Web Apps That A Web Designer Should Know About
Modern Web Development
Ultimate List of HTML5 and CSS3 Tools | Admix Web
great tools that can help you to master these new features of both HTML5 and CSS3
ProtoFluid - HTML5 and CSS3 Web App Prototyping
Test your @media queries and web app on various screen sizes
HTML5 Readiness
Compare browser support of HTML5/CSS3 features