I can agree in that CGI is a cool and simple technology that might make sense for some applications, and can be a good method to teach new developers the basics

I can agree in that CGI is a cool and simple technology that might make sense for some applications, and can be a good method to teach new developers the basics. I don't think I'd choose it for much now though, unless I knew it was very simple and would never grow more complex. Most of the complaints here are about performance. I don't think the decreased performance would be much of an issue until you get to pretty large scale. I do think the real issue is the huge complexity in doing things correctly and securely in such a manual environment. Oh, you're going to do cookies by just printing the Set-Cookie header manually? Well now you have to handle everything about your cookies manually and do it correctly. What are the odds you're doing that? Just let Rails etc handle it the right way for you. Going to do CSRF protection manually too, and do anti-XSS escaping correctly everywhere, and mitigate a ton of obscure security issues that most people have never heard of? No way, unless you're a world-class expert. Just use one of the major proven frameworks that already take care of all of that stuff for you.