The front end for the dmd D compiler is open source. The back end for dmd is licensed from Symantec, and is not compatible with open-source licenses such as the GPL. Nonetheless, the complete source comes with the compiler, and all development takes place publicly on github. Compilers using the DMD front end and the GCC and LLVM open source backends are also available. The runtime library is completely open source using the Boost License 1.0. The gdc and ldcD compilers are completely open sourced.
