D is somewhat backwards compatible with C, you are also able to use the C std library too. But what C? C89, C99 or C1X? GCC 4.6 introduces some features of C1X. Some info about the upcoming standard: http://en.wikipedia.org/wiki/C1X
In C1X there is _Noreturn, it seems interesting: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1453.htm In C++0x it's [[noreturn]], and the nonstandard GCC extension is __attribute__((noreturn)). There are also the gets_s() function that replaces gets(), and aligned_alloc(). Bye, bearophile