I might be misguided, but the last time I used PHP was over ten years ago, using PHP3, and we had to name the files my_file.php3 in order to use PHP3. That's th

I might be misguided, but the last time I used PHP was over ten years ago, using PHP3, and we had to name the files my_file.php3 in order to use PHP3. That's the opposite of minimal breakage. On the other hand, my simple PHP3 scripts continue to work to this day, php3 extension and all!