Before PHP became widespread in the very late 90s there were many options for dynamic apps. I worked with ISPs which offered CGI or SSI even on cheap / free plans. Sure, it was ugly but a ton of people got what they needed done by going over to Matt's Script Archive and finding something they could hammer into shape. Before antique PHP apps, the security cliché was formmail.pl & a slew of long-forgotten guestbook / forum scripts.
I'm not saying that PHP didn't help considerably, only that it was very far from first. I remember having to make the case for using PHP 2 or 3 instead of many of those alternatives and it was based on cost and convenience, not the ability to do anything new.