Ada uses a garbage collector for the free store (or just uses unsafe code if it's disabled). Ada's memory management model is not really different from any other typical language.
This is the first time I've ever heard of Ada being garbage collected. Neither
ARM, Barnes' nor Ben-Ari's books, nor GNAT manual say that there is supposed
to be a garbage collector (quite the contrary, the books say that GC is
allowed, but usually not present).
