[bradcray]

@mardifoufs: I realize that your point is that the Chapel webpage didn't answer this question clearly / concisely for you and agree that we could and should improve that. The observations in this thread have definitely helped given me insights about how we could position ourselves better for the non-HPC audience (and I already have a longstanding intention to make the code sample on the page more compelling using Asciinema that I need to find the time for).

But to answer your specific question here: I'd say that most mainstream languages (e.g., C, C++, C#, Java, Python, Rust, Swift, ...) don't aspire to scalability in the same sense as Chapel and High Performance Computing want it, in the sense of being able to run efficiently on tens of thousands of processors with distributed memory where inter-processor communication and coordination is required. And even when they do aspire to it, it's rarely through the language itself, but through communication libraries, pragmas, and extensions. The result (in my opinion) is rarely as productive, general-purpose, and performant Chapel achieves.