They don't now. The spec will almost certainly allow some form of dynamic code generation/loading in the future http://webassembly.org/docs/future-features/#pl

They don't now. The spec will almost certainly allow some form of dynamic code generation/loading in the future http://webassembly.org/docs/future-features/#platform-independent-just-in-time-jit-compilation http://webassembly.org/docs/future-features/#platform-indepe...