Remember Matt's Script Archive? That was all Perl and covered a lot of the hit counter, contact/guestbook and forum software pre-PHP.
My first website back in `96 also had some compiled C via cgi. No database. I've said this before but using compiled Go with the web brought back memories of those good old days.
I spent about 4 years doing classic ASP before .Net arrived and had a hand in building a lot of big sites some of which still exist (and still use ASP): Most corporate jobs seemed to use the Microsoft stack then (or Java), where PHP was the what you did on the side because it didn't require server licensing.
It's often overlooked that many of the cheap hosting companies who provided the environment for PHP's phenomenal growth only offered PHP as a CGI. You often had to pay a lot more if you wanted mod_php because it was harder to secure and required more resources. PHP/CGI was the way to max out the number of users on a server even it was slower.
> PHP's killer feature was mod_php. It was dead simple to integrate into any shared hosting environment, and so pretty much every shared host did
Also safe_mode and open_basedir, which promised shared hosting providers that their users wouldn't hack the server and each other
Some folks were also compiling C and gluing it together with a CGI module, and a lot of others in the Microsoft world were using Frontpage and its brethren. But, the Microsoft stack only ran on Windows servers, and Windows web servers had a reputation (deserved, imo) for kinda sucking.
PHP's killer feature was mod_php. It was dead simple to integrate into any shared hosting environment, and so pretty much every shared host did. mod_php magically knew how to spit out html when reading html, and execute php when encountering php tags, so that gave us the html-mixed-with-php pattern that was wonderful at the time but considered bad practice now.
But also scope has changed a lot. At the time, people were mostly looking for hit counters, contact forms, and "guestbook" forms. For all those things, PHP excelled, so it gobbled up the market fast.