It's absolutely doable in HTML+Js - I've written a TableView in GWT that utilizes the exact same principle and was actually inspired by Cocoa's TableView API. I

It's absolutely doable in HTML+Js - I've written a TableView in GWT that utilizes the exact same principle and was actually inspired by Cocoa's TableView API. It could render thousands of rows (or however many) utilizing only a few actual divs.