Facebook has made a C-Preprocessor. D is great for such command line tooling. The standard library is not as extensive as Python's, but the situation is much better than in C-land. You can also use it as a scripting language.
D has a nice framework for servers (vibed.org), so you can write webservices (REST,JSON,etc). There is no great full-stack web framework like Rails or Django though.
GUI stuff works in theory, but I don't know any non-toy project. Games (OpenGL,SDL) are possible, but no serious project, yet.
Android/iOS does not really work, yet. Same with embedded, standalone, kernel stuff. ARM in general needs more work.
For HPC it really depends on the use case (see dlangscience.github.io).
Vector support and GPU integration is lacking.
I don't know any image, video, or audio processing stuff in D.
Actually, that C Preprocessor was written by Walter Bright for DMC; just about every file has his copyright notice, and no Facebook copyright notice. I think they just translated it from C++ to D.
D has a nice framework for servers (vibed.org), so you can write webservices (REST,JSON,etc). There is no great full-stack web framework like Rails or Django though.
GUI stuff works in theory, but I don't know any non-toy project. Games (OpenGL,SDL) are possible, but no serious project, yet.
Android/iOS does not really work, yet. Same with embedded, standalone, kernel stuff. ARM in general needs more work. For HPC it really depends on the use case (see dlangscience.github.io). Vector support and GPU integration is lacking. I don't know any image, video, or audio processing stuff in D.