How much of the source level semantics do you want to preserve? If you don't care about many of them then it's not too hard to do (although quite pointless). Ju

How much of the source level semantics do you want to preserve? If you don't care about many of them then it's not too hard to do (although quite pointless). Just compile to an array of bytes, and a turing machine emulator or equivalent, in your target language of choice, and you've converted. The hard part comes when you want to preserve source-level semantics and provide a natural-feeling translation so that a human can understand, read, and write the source. However, with a VM you don't have that problem. With a VM, a lossy, one-way transform is sufficient. You can easily throw away information as you compile, since you're not targeting humans consumption for the output. You can replace, say, overloaded functions with mangled names. You can turn multiple dispatch into decision trees of conditional statements. And so on. With a VM, you would want to keep enough high-level detail to efficiently JIT stuff, and it's a bit of a challenge to decide what detail is sufficiently useful to include, but it's not insurmountable.