D seems like a cool language. Do many people use it?

D is an interesting case study for good technology somehow not succeeding. The people working on it are very good and it's a really interesting language. In theory it should slowly have taken over from C++ but for whatever reason this didn't happen.

- Go is backed by Google.

- Rust is backed by Mozilla.

- C# is backed my Microsoft.

- D is backed by... D users... and the two language architects.

A few schools use it. A few companies use it.(::cough::This little company called Facebook::Cough::)

The other is target market. D appeals to a new, or more advanced kind of programmer. A new niche or category. A programmer that doesn't get produced at most colleges, or demanded by most companies. And if they're not produced or demanded, that category isn't going to fill up with programmers. Nobody would have used Java if schools across the nation didn't tell kids that "Java was cool" and the JVM wasn't something to be afraid of.

There are categories of programmers. No one can say that a LISP programmer is quite like a C programmer.

- C programmers want "nicer assembler." C.

- C++ programmers don't want a GC. (Though D is working toward a GC-less standard lib.)

- Python/Java/C# programmers are (more likely to be) afraid of systems languages that can segfault like crazy if you don't know what you're doing.

D appeals to programmers who aren't afraid of the entire stack. They write, understand or at least appreciate assembler and caches, while also dabble in high-level templates and functional programming.

I can absolutely say I've grown as a programmer after looking through D features and going, "Why don't I know how that works?"

The guys behind D are brilliant, and professional. Watch any of their talks. Andrei Alexandrescu works for Facebook and still writes plenty of C++. He also wrote THE quintessential "Modern C++ Design" book on template meta-programming. And Walter Bright has been writing compilers for decades.

This is not a toy language.

Here's plenty of benchmarks showing D as fast as (and sometimes beating) C/C++ _and_ having low memory usage.

https://github.com/kostya/benchmarks

Meanwhile, the benchmark is misleading. Because not only is generally as fast as C/C++, but it's way more productive to write in.

But back to adoption. It's simple. 1) No corporate backers pushing it, 2) A language for advanced/multi-talented programmers is either scary or "unnecessary" to single-talented programmers.

Most C programmers are afraid of, or think templates are unnecessary. Most C++ programmers are afraid of a garbage collector (even if it's a completely deterministic one that only fires off during specific allocation points).

As a mostly C++ programmer, I was apprehensive of D's GC. But the more I read, the more confident I've been, and, I've had zero actual problems with it. I'm pushing 130 FPS on my netbook just fine, and because D isn't a toy language, I can easily move to static pools and have zero GC allocations.