By my count, most "regex" engines implement things more powerful than regular expressions. I'd say the majority of regex engines use backtracking instead of a D

By my count, most "regex" engines implement things more powerful than regular expressions. I'd say the majority of regex engines use backtracking instead of a DFA. Backtracking does tend to be slower in my experience, but PCRE2's JIT is definitely competitive with even the fastest DFA engines in my experience.