In spite of my status and obvious bias as co-creator of D, I'll do my best to answer candidly; I follow Go and Rust, and I also definitely know where D's dirty laundry is. I'd encourage people with similar positions in the Rust and Go communities to share their honest opinion as well. So here goes.
First off, C++ needs to be somewhere in the question. Whether it's to be replaced alongside C, or be one of the candidates that's supposed to replace C, the C++ language is a key part of the equation. It's the closest language to C and the obvious step up from it. Given C++'s age, I'll assume in the following that the question also puts C++ alongside with C as a target for replacement.
Each language has a number of fundamental advantages (I call them "10x advantages" because they are qualitatively in a different league compared to at least certain baselines) and a number of challenges. The future of these languages, and their success in supplanting C, depends on how they can use their 10x advantages strategically, and how they overcome their challenges.
[Another way to look at this is to ask "What is wrong with C?" and then assess how well these languages solve those problems. -Ed.]
(Score: 2) by turgid on Friday November 13 2015, @02:50PM
Not in timing-critical code and/or on the bare metal. Having said that, D naturally uses the C ABI and knows about C libraries so there should be no problem using standard C libraries.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].
(Score: 0) by Anonymous Coward on Friday November 13 2015, @03:30PM
But if you're going to use standard C libraries anyway, then why not just use C to begin with?
(Score: 2) by turgid on Friday November 13 2015, @03:35PM
Because perhaps the other language is more powerful and let's you achieve more with fewer lines of code?
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].