While Chakra is most closely associated with Edge, it does more than power this web browser. Seth added that Chakra supports "Universal Windows applications across all form factors where Windows 10 is supported--whether it's on an Xbox, a phone, or a traditional PC. It powers services such Azure DocumentDB, Cortana and Outlook.com. It is used by (and optimized for) TypeScript. And with Windows 10, we enabled Node.js to run with Chakra, to help advance the reach of Node.js ecosystem."
ChakraCore's MIT License is an extremely liberal license. Essentially, so long as you include the copyright notice, you can do anything you want with the code. So, if you wanted to make your own Edge clone, you're at liberty to use one of its key components.
Seth also hints that Edge may eventually come to Windows 7. He wrote: "With today's release, you can build ChakraCore on Windows 7 SP1 or above with Visual Studio 2013 or 2015 with C++ support installed."
It's not just Windows 7 that may see some Edge goodness. On the ChakaCore roadmap, Seth wrote that by June 2016, Microsoft wants to release "an implementation of ChakraCore interpreter and runtime, no JIT, on x64 Ubuntu Linux 15.10."
Yes, that's right. Microsoft is porting part of an end-user program to Linux.
Linux's father, Linus Torvalds, once said, '"If Microsoft ever does applications for Linux it means I've won." I'd say he's won.