[cpeterso]

JXcore is another fork of Node that makes the VM pluggable, supporting both V8 and SpiderMonkey. I wonder how similar Microsoft's and JXcore's VM abstraction layers are and whether Node upstream would accept them. Drawing a hard line between the Node native code and the VM would make binary addon compatibility more stable (and lessen the need for NaN, the "Native Abstractions for Node").

[streamline92]

The problem with the way JXcore did the SpiderMonkey port is their extensive use of C++ macros - not unlike NAN for Node.js. This makes the code hard to debug and maintain. The Microsoft Chakra Node port is more elegant because they've mimicked the V8 C++ API making it much more likely that it will be merged into Node.js and IO.js. In time I suspect Mozilla and other javascript engines will make V8-compatible API shims similar to what Microsoft did:

https://github.com/Microsoft/node/tree/ch0.12.2/deps/chakras...