Designed by Vernon Adams
Antonio is a 'refined' version of the Anton Font. Anton is a single weight web font, designed specifically for larger display, headline and 'banner' use (see Google's PR for the Chromebook notebooks that used Anton, big and bright).
Antonio extends the Anton design to include more weights and introduces refinements to the design that makes it also suitable for use in smaller headings, menus and 'buttons' etc.
To contribute, see github.com/googlefonts/antonioFont
You can download font files directly and install them with Font Book. However, it’ll be much easier to install these fonts with RightFont — the best font manager for Mac.
These fonts are licensed under the Open Font License.
You can use them freely in your products & projects - print or digital, commercial or otherwise.