Re: concurrency, D's concurrency story is really quite good. It may not be built upon as sound a logical model as Rust's (few languages can compete there), but

Re: concurrency, D's concurrency story is really quite good. It may not be built upon as sound a logical model as Rust's (few languages can compete there), but it has very good ergonomics, and offers a nice range of concurrency strategies. See std.concurrency, std.parallelism, and vibe.d: - http://dlang.org/phobos/std_concurrency.html http://dlang.org/phobos/std_concurrency.html - http://dlang.org/phobos/std_parallelism.html http://dlang.org/phobos/std_parallelism.html - http://vibed.org/ http://vibed.org/ std.parallelism and vibe.d in particular are absolute pleasures to work with. As a framework, vibe.d is well designed to avoid unnecessary allocation and runs very efficiently. D's current GC is quite poor, that's a common complaint. But the recent and forthcoming "nogc" changes are making a significant difference -- it's increasingly easy to avoid the GC altogether.