But it will take years to build a library ecosystem that can rival the python one.
But it will take years to build a library ecosystem that can rival the python one.
My personal killer app would be a significantly revamped plotting library/app. While matplotlib is great, it is fundamentally based on imaged-based plotting. The next generation of data visualization, imo, will likely be interactive. Having an interactive plotting library that allows you to produce publication-quality plots faster and simpler (think of all the time spent aligning text manually..) could be a big deal, but it could also not matter as no one else wants the same things I do.
Ecosystem; mind-share; readability and engineering mind-set; history/Numpy/Matlab; teachability and academic focus.
There are also comments emphasizing the "dynamic" scientific environment and need to just pick up code left by others.
In terms of the latter, could one apparent requirement be this: The main contact should be with top-level code which at least looks like it is interpreted -- even if through compile-with-run-combined and/or memoization? Need part of the user interface, so to speak, be to hide all intermediate artifacts, even the very thought of object code and executables? That such stuff is for, say, "module creators" not primary users?
Personally, I find that many Fortran codes are still used because they have been build for many years, and they can't be rewritten easily. On the other hand, new data science projects start all the time, and the transition to Julia is easy (and worth it in my opinion). That means that in my experience, Julia is mostly competing for marketshare with NumPy/SciPy/SKLearn/Pandas/R/Matlab.