The code is now available to download from the ChakraCore GitHub repository. Microsoft says:

"The ChakraCore repository provides a fully supported and open-source standalone JavaScript engine, with the same characteristics as the Microsoft Edge's Chakra engine, to embed in projects, innovate on top of and contribute back to. We will be accepting community contributions and input to ChakraCore. Once the changes from any pull request have been vetted, our goal 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."