Since its launch, Google’s Chromium project has been a desktop-only matter, but that changed in 2015 with the addition of the Android version. Following that, only the iOS version of the browser wasn’t open-source. However, that’s changing today as Google has announced that the code for Chrome on iOS has been moved into the Chromium open-source repository.
Google has announced that after years of keeping Chrome for iOS separate from its Chromium project, it is now open-sourcing the browser on Apple’s mobile platform. Despite the “additional complexity” associated with the platform, the company says that its team spent a lot of time over the past several years to make the necessary changes required to upstream the code for Chrome on iOS into Chromium.
If you are wondering why Chrome for iOS was kept separate from the Chromium project even though Android version joined Chromium back in 2015, this is because the iOS version of the browser is built on top of the WebKit rendering engine instead of Google’s Blink engine. Due to the constraints associated with iOS, all browsers must be built on top of WebKit rendering engine, Google reminded readers in its blog post.
“For Chromium, this means supporting both WebKit as well as Blink, Chrome’s rendering engine for other platforms. That created some extra complexities which we wanted to avoid placing in the Chromium code base,” it added.
As for what this means for Chrome users, there won’t be any major changes on the surface. Rather, Google explains that the speed of developing new versions of Chrome for iOS will be accelerated since tests can now be run with the entire Chromium community. This also means that third-party developers on iOS have a new “starting point” for developing their own browsers, similar to Opera on macOS.
Due to constraints of the iOS platform, all browsers must be built on top of the WebKit rendering engine. For Chromium, this means supporting both WebKit as well as Blink, Chrome’s rendering engine for other platforms. That created some extra complexities which we wanted to avoid placing in the Chromium code base.
Given Chrome’s commitment to open-source code, we’ve spent a lot of time over the past several years making the changes required to upstream the code for Chrome for iOS into Chromium. Today, that upstreaming is complete, and developers can compile the iOS version of Chromium like they can for other versions of Chromium. Development speed is also faster now that all of the tests for Chrome for iOS are available to the entire Chromium community and automatically run any time that code is checked in.
We value the open source community and all of our contributors, and we’re glad that Chrome for iOS can finally join in.