Every time I hear about D it sounds awesome. I actually used it to prototype an image collage-composing algorithm which I then rewrote in Scala[1], and the D version might have been nicer to write.

The only reason I didn't write more stuff in D was that the stack traces from my programs were pretty much useless. Maybe I was supposed to set a --better-stack-traces flag when I compiled it or something idk.

[1] One of the algorithms used by https://github.com/TOGoS/PicGrid