With Ice Cream Sandwich, Google introduced Roboto to the world. Since then, the family (designed by Googler Christian Robertson) has expanded to include a set of slab serif fonts, and has even seen a major revision introduced with Android 5.0 last year.
According to Google, the effort to open source Roboto succeeded thanks to collaboration between material design, internationalization engineering, Google fonts, and Android teams.
For reference, the family now includes more than 40,000 total glyphs which span all Latin, Cyrillic, and Greek characters, making Roboto an immensely informative family to study.
You can find the new Roboto project on Github here, or check out Google's blog post below.
- Google Open Source Blog