Though I don't quite understand the subject line, it marks a recent thread
on the gnat-chat list.  From the description of the features of this "ODD"
(ACT's odd heterological acronym for it) item, it may not be fully a
"killer" but it could certainly get some good exposure for Ada.

 * Entirely written in Ada - presumably with the reliability that
   implies.

 * GUI interface for the 'gdb' debugger

 * Supports items available in Ada and not in C (possibly including Java
   threads and Java/C++ exceptions?)

 * Uses Tk bindings, therefore portable to X11, WinDoze, Mac

 * Native code, therefore faster than interpreted Java.

 * Ada and Tk, therefore easier to read and much smaller than Java.  This
   is my guess--I haven't seen it, but I've written a small amount of Java
   GUI code, and it sure takes a heck of a lot more SLOC than TCL/Tk for the
   same effect.)

 * Can run on a different platform than the one running gdb

 * Can control multiple gdb sessions (debugging distributed programs?)

 * "Entity browsing" (click on something, view its declaration).

--
Wes Groleau
http://freepages.genealogy.rootsweb.com/~wgroleau