D is a relatively new language that, like ObjectiveC, tries to address some of the more serious problems in C++. From our interview with Cristian Vlasceanu,
In many ways D encourages the "right" behavior. For example, in C and C++, if you write "int i;" the variable is uninitialized. To do the "right thing", the programmer needs to type extra keystrokes as in "int i = 0;" but D works the other way around: "int i;" safely sets the variable to a default value (that in this case is zero). To make it uninitialized you have to spend extra effort and type "int i = void;" expressing that the uninitialized variable is intentional and not due to laziness.
D.NET is an experimental port of the D language to the Common Language Runtime. It consists of two parts, a front-end and a back-end component. The front-end component handles the parsing of source code and the generation of abstract syntax trees. The back-end compiler takes that and generates the actual machine code, or in this case IL code. While the source for both are available on CodePlex, only the back-end is maintained there. The front-end component is straight out of the D 2.0 Programming Language Compiler.
A word of caution,
The back-end code is not of production quality, it is intended for research and educational purposes. The D Programming Language is a fairly complex language, and non-trivial features such as TLS and closures make it an interesting case study for generating IL code.