Created by ZURB, they created these icons with specific standards which gives a cohesive voice and style to develop an amazing font set for everyone to love, enjoy and use on their website. Some standards includes:
Geometric
All icons are made with basic shapes like triangles, squares, rectangles and circles.
Round Corners
All icons are made with rounded corners to give the icons a softer and more approachable feel.
Thick Line Weights
All icons opt for a thicker line weight as opposed to thin lines so that the icons could be scalable, as well give it the friendly look we're going for.
Natural Angles
We've given these specific rotation degrees to maintain the consistency as a set.
Scalable
When creating these icons, we are thoughtful with how these icons would scale at small and large sizes.
After converting these vector icons into a font, we’ve given you the ability to have an endless number of sizes, colors and styles for the icons that you need which could be customized and stylized via CSS.
Here is the documentation for the latest version "Foundation Icon 3".