In case others were curious to look up the timeline, WP says first validated GNAT release was in 1995, vs 1983 for the earliest validated implementation. (but

In case others were curious to look up the timeline, WP says first validated GNAT release was in 1995, vs 1983 for the earliest validated implementation. (but perhaps the earlier stuff wasn't practical: "Early Ada compilers struggled to implement the large, complex language, and both compile-time and run-time performance tended to be slow and tools primitive" ... "By the late 1980s and early 1990s, Ada compilers had improved in performance")