Microsoft open-sources its JavaScript engine Chakra

As promised, Microsoft has open-sourced the core components of Chakra, the company’s JavaScript engine used in Microsoft Edge and Internet Explorer. The project, dubbed ChakraCore, has been released under the MIT License on GitHub.

Aside from powering Microsoft’s browsers, Chakra also helps power Azure DocumentDB, Cortana, Outlook.com, TypeScript, and Node.js in Windows 10 IoT Core, as well as universal Windows 10 applications across Xbox consoles, smartphones, and PCs. In other words, Chakra has become an increasingly important base for many divisions across Microsoft.

The fully supported and open source project includes everything needed to parse, interpret, compile, and execute JavaScript code without relying on Edge. Starting today, Microsoft is developing the key components of Chakra in the open, and is accepting community contributions and input to ChakraCore. The goal, the team explained, is “to ensure that all changes find their way to be shipped as a part of the JavaScript engine powering Microsoft Edge and the Universal Windows Platform on Windows 10.”

Microsoft last month said it expects ChakraCore to be deployed in anything from cloud-based services to the Internet of Things. The company specifically named NoSQL databases, productivity software, and game engines.

Developers are already diving into the code:

purity-testing JS engines.

ChakraCore:
? JavaScript 56.2%
? C++ 37.9%

v8:
? C++ 74.0%
? JavaScript 25.8% pic.twitter.com/1Kt1zMb5D7

— Jed Schmidt (@jedschmidt) January 13, 2016

Microsoft also previously described the initiative as “a fully-fledged, self-contained JavaScript virtual machine that can be embedded in derivative products and power applications that need scriptability.” Today’s release can be built on Windows 7 SP1 or above with Visual Studio 2013 or Visual Studio 2015 (C++ support must be installed).

But the company isn’t stopping at Windows. Microsoft plans to bring the project to other platforms, starting with Linux. In fact, the team has separated Chakra’s JIT compiler just for this purpose. Building just the interpreter and runtime makes for a smaller build target that is easier to work with for cross-platform porting.

If you’re interested in learning what else is in the pipeline, the roadmap is also available on GitHub.