No mention of Solaris Studio, which is something I've always been curious about. Unlike most (all?) of those others it can use a completely different compiler than gcc or clang.
Perhaps I've simply been scarred by the nineties, but back in the day /opt/SUNWspro was an extremely rich source of mysterious WTFs and much profanity.
It has definitely had its annoying moments from time to time tho.
I haven't used it in years, and don't even remember what was so great about it, I just remember it seemed a lot better than gdb at the time.
From the dbx wikipedia page:
DBX is included as part of the Oracle Solaris Studio product from Oracle Corporation, and is supported on both Solaris and Linux. It supports programs compiled with the Oracle Solaris Studio compilers and GCC.
The only reason I haven't played with this to satisfy my curiosity is that they are pretty specific about what distributions they support, and they don't support mine.