The new icons have much more lightweight shapes than the previous ones. They are just discreet lines on a clean canvas. Previously we used a combination of bolder icons from different authors, mainly from the excellent Glyphish sets. Our new set is heavily influenced from the previous sets. It's just redesigned in-house by ourselves to be lightweight and more balanced, more consistent as a whole. The light icons are especially good-looking on high definition (Retina) screens.
Here's the comparison of the old and new icons:
We've made our new icons completely free to use, edit, change and rebuild for everyone in their own projects. Download the icon pack here in Sketch or SVG format. Enjoy!
You can find other things that we have open sourced, like our rich text editor, from here.