The reference D compiler is now open source
Good news indeed.Switched to D 4 years ago, and have never looked back.   I wager that you can sit down a C++/Java/C# veteran, and say write some D code.   Here's the manual, have fun.    They will with in a few hours be comfortable with the language, and be fairly competent D programmer.  Very little FUD surrounding the switching to yet another language with D.D's only issue is that it does not have general adoption, which I'm willing to assert is only because it's not on the forefront of the cool kids language of the week.   Which is a good thing.  New does not always Mean, improved.  D has a historical nod to languages of the past, and is trying to improve the on strengths of C/C++ and smooth out the rough edges, and adopt more modern programming concepts.  Especially with trying to be ABI compatible, it's a passing of the torch from the old guard to the new.Regardless of your thoughts on D; My opinion is I'm sold on D, It's here to stay. In 10 years D will still be in use, where as the fad languages will just be foot notes in Computer Science history as nice experiments that brought in new idea's but were just too out there in the fringes limiting themselves to the "thing/fad" of that language.