Existing Python libraries can be called quite easily from Julia using PyCall (https://github.com/stevengj/PyCall.jl https://github.com/stevengj/PyCall.jl) Rega

Existing Python libraries can be called quite easily from Julia using PyCall (https://github.com/stevengj/PyCall.jl https://github.com/stevengj/PyCall.jl) Regarding ecosystem development, one advantage that Julia has is the low learning curve between "user" and "contributor". Idiomatic code usually runs reasonably quickly, and can be made "fast" by tweaking some things within the same language (devectorizing, or turning off bounds-checks, for example). These kinds of optimizations simply cannot be done in NumPy without dropping in to C+CPython or Cython (each of which has impedance mismatches and language+toolchain hurdles).