CSS Flexbox is one of the biggest additions in CSS, in over a decade. The purpose of CSS Flexbox is to give web developers a stronger and more flexible grid system to build with. This is especially important nowadays, with greater emphasis on building websites that can perform equally as well on mobile, tablet and larger screens. The aptly named FlexBox stack aims to encapsulate almost all aspects of the CSS Flexbox specification and deliver one of the most comprehensive layout stacks available for RapidWeaver to date. The FlexBox stack can confidently build any 2-dimensional grid layout, asked of it.