In addition to the Edge browser, Win10 will also support the Chakra Javascript engine

Computer Store News: We know that Microsoft Edge browsers and Win10 Windows applications written in HTML/CSS/JS are driven by the Chakra JavaScript engine. And many developers are asking Microsoft to support the Chakra engine outside of the browser to enable cross-client and server JavaScript programming support for their native/managed applications. In the Windows 10 environment, Microsoft is making some major improvements in this area.

Microsoft wrote in the official Windows blog: "In Windows 10, we have made significant progress against the JSRT API, allowing them to support Chakra engines across different application types. Get the highest priority. Developers can now use these APIs to add Chakra engine support in scripting classic Win32 applications and general Windows applications. These APIs now provide underlying access and support for the generic Windows platform and ECMAScript 6, respectively. For example, the Chakra-based Node.js platform recently released for Windows 10 IoT devices was built using these APIs. ”