Google introduced the Roboto font nearly four years ago as part of Android 4.0 Ice Cream Sandwich. Since then, it's grown to be the default for Android and Chrome OS, and it's a big part of Google's overall Material Design language that we're seeing spread across many of its web services (like Inbox and Google Play Music) as well. Google released the font to the public not long afterwards, but today the company's taking things a step further and making the font open source — everything related to Roboto is now up on GitHub, including a "revamped font production toolchain" that was used to create the font in the first place.
It's an interesting move for Google — the company freely admits in its blog post announcing the release that Roboto has become a bigger and bigger part of Google's identity over the years, but now that key part is freely available for anyone to modify. It's the kind of move we wouldn't expect to see from Apple, which developed its own signature font alongside the Apple Watch. That new font (named San Francisco) is expected to be included in future versions of iOS and OS X, but we're not holding our breath for Apple to release it and let the public start messing around with it. If you want to start playing with Roboto, though, feel free — it's all available right here.