[pekk]

Clojure isn't really a fair comparison. Clojure hasn't got low-level interop with all those things, just JVM, and that interop is bought at the cost of closely tying Clojure to JVM. I don't think D can be changed in all the basic ways that would be required to give it the same level of integration with JVM, and that would also basically mean abandoning the entire standard library. JVM's difficulties integrating with things other than JVM aren't something I imagine D can really solve.

[jeremiep]

I meant things such as extern(C#) and extern(Java) to work the same way extern(C) and extern(C++) do now.

I don't see the point of compiling D to JVM or CLR byte-code for all the efforts it would involve, but rather the CLR or JVM load native code written in D and have each call into each other easily.

Say I can't reach the performance I want in C# and I want to write that part of the system in D and load it in Unity and then call into native D code from there. Without having to mess with the CLR implementation details. That would definitely allow people to try it out and integrate it gradually until it has completely taken over.