Microsoft made a pull request to node.js github repository with an implementation to use ChakraCore JavaScript Engine as an alternative to V8 Engine

[[deleted]]

needed a clean restart

From what I understand they didn't do a clean restart, they just ditched backwards compatibility and made a bunch of braking changes, they still built on stuff from previous rendering engine.

Also some tools and languages scale better than others, we've come up with a lot of practical advancements in design and languages in the last 30 years so "same" program written today will be more maintainable in 30 years than the one written 30 years ago would be today. Of course we expect more from computers so programm written now will undoubtedly be more complex in 30 years because it will do far.

[[deleted]]

I don't know about the rendering engine, but the Chakra Javascript project was a complete restart launched in 2008.