Sane javascript in Unreal 4 is definitely interesting, however, take a look at the repo's owner. This has a lot more staying power as a portion of the platform

Sane javascript in Unreal 4 is definitely interesting, however, take a look at the repo's owner. This has a lot more staying power as a portion of the platform given the fact that NCSOFT, producer of Guild Wars and Aion, is the company behind it; this isn't a hobbyist hacking together a solution to build a proof of concept, this is a giant publisher potentially throwing their weight behind their new platform. Their new, opensource platform.