I did something similar (same time frame) that definitely manipulated the DOM, but I didn’t keep the HTTP connection open, I used hidden Iframes. Clicks got red

I did something similar (same time frame) that definitely manipulated the DOM, but I didn’t keep the HTTP connection open, I used hidden Iframes. Clicks got redirected to the iframe, which returned <script> elements that would replace DOM elements (in the parent frame) using their .innerHTML. AJAX streamlined the process, but there were a lot of hacky ways to get similar dynamic HTML effects. I like the idea of keeping the HTTP connection open, but that seems quite resource intensive… particularly for the early 2000s.