For Julia core it should be feasible, but possibly requiring patches to Emscripten, so the level of effort is still unknown. The other issue is the C and Fortra

For Julia core it should be feasible, but possibly requiring patches to Emscripten, so the level of effort is still unknown. The other issue is the C and Fortran numerical libraries -- some of which use inline-assembly, others (Fortran) don't have a working LLVM frontend as far as I know.