React, Flux, GraphQL, Hack, HHVM...? All of this and more!
Microsoft originally embedded the Chakra engine to it's Internet of Things version of it's flagship Windows 10 Operating System. The IoT iteration of Windows 10 runs on limited hardware on the ARM processor architecture and Microsoft had to optimize to get Node.js to run on it, this was done using Chakra instead of Google's V8 engine.
Some of the older farts in the tech community have some deep antipathy against anything coming from Microsoft. The company has had to open up since it's Windows monopoly is gone and it now has to play on a more level playing fields, where as Google still dominates the seach engine world.
Time will tell if it will gather significant marketshare or whether it will be a curiosity, but it is likely that deploying Node.js applications to Microsoft's cloud platform Azure will eventually be powered by the Chakra engine. In any case Node.js enthusiasts should welcome the new option as an alternative to the V8 engine.