The Roboto family of fonts, and the toolchain used in creating it, are now an open source project. Roboto is Google’s signature font, created by Google designer Christian Robertson. It is the default font used in Android and Chrome OS, and is the recommended font for Google’s visual language, Material Design.
The font files for the Roboto family of fonts were first released under the Apache license as part of Android 4.0 (Ice Cream Sandwich) in 2011. With this launch, we are making Roboto a true open source project, with a revamped font production toolchain that is completely based on open source software.
Another key improvement in the Roboto font family has been the vast expansion of its character coverage to include all Latin, Cyrillic and Greek characters in Unicode 7.0, as well as the currency symbol for the Georgian lari, to be published in Unicode 8.0. For the expansion, the number of glyphs provided in the fonts more than tripled in number, going from around 13,000 (1071 per font) to more than 40,000 (3350 per font). An earlier version of the expanded font family is included in Android 5.0 (Lollipop) and later.
This project involved close collaboration between various teams at Google: Material Design, Internationalization Engineering, Google Fonts and Android.
The Roboto open source project lives at https://github.com/google/roboto. Bug reports and other contributions are welcome.

By Roozbeh Pournader, Android Text team