Client-side includes would have been useful. Could have mostly avoided the need for frames and iframes, which would have saved time and effort.

XHTML was a big distraction. I wish the whole thing had been avoided.

Dynamic HTML was really cool at the time, but the divergence between Netscape 4 and IE 4 was a real pain — I wish they had agreed on standards earlier.

Lastly, the way Microsoft screwed over developers when they 'won' the early browser wars, and then abandoned work on IE for 5 years after version 6, which left the web to stagnate. I wish someone could go back and force the fuckers back into the game.

Using HTML to describe documents and letting browsers handle the UI rendering, instead of providing UI primitives/widgets like Winforms in Visual Studio. We've spent the next two decades reinventing everything from modals to combo boxes that worked fine in Windows 95 GUI apps...

You can't change case-sensitivity in URLs, because they contain path names which are handed directly to the operating system on which the server runs. So the sensitivity follows the OS (whose design is unrelated to and usually predates web development).

When I say can't, I mean it's just a monumentally bad idea, that it amounts to shouldn't even try.

Not quite web dev but I've always thought there might be room for a browseresque class of software for mobile apart from the literal browser. Instead of every mom and pop shop having basically similar apps that everyone feels resentful of installing, just have a bunch of the shared functionalities bundled into a meta app. The app browser could handle things like identity/billing/notifications etc.

The mini-apps could be mostly a JSON object defining behaviors and then maybe some styling/assets. It could lower the cost of getting a proper mobile experience out for businesses as well as lower the friction for a user debating installing an app.

It seems a shame that the choice is between a responsive webapp and a really expensive (dev time wise) native app.

JavaScript is definitely at the top of my list.

I don’t think there’s a main single technical issue with web. But if it counts, I’d go back and put less sleepy people to rule web standards. So that they could sit together and clearly see what it lacks fundamentally and add it there instead of waiting for ten years for each feature. Also they would just expose lower-level interfaces, so things like flexbox or content queries could be implemented by simply hooking up js callback into a sizing loop, etc. As if they were proper programmers and knew that a generic solution is just better than a bunch of specifics from the evolutionary pov.

I could be wrong in this. Please educate me if so.

I’m thinking they should have made flash open source and iPhone should have run it. It was a pretty amazing technology.

The CSS box model for sure. Border box just makes so much more sense than content box (who seriously counts the width of a border and padding as separate from the container itself, in real life or otherwise?) that I'd put it as default from the start, like IE did all along.

I'd probably also scrap the attempts to migrate to XHTML, and go ahead with HTML 5's additions back in the early 00s. Things like the new semantic block elements, new input types, picture element, etc are far more useful to developers than an XML based HTML dialect were, and don't sacrifice ease of use for some abstract ideal.

Finally, I'd have Flexbox and Grid added early on, so that the hellscape of floats and table layouts didn't have to come to fruition. They just make so much more sense really.

Buggy DOM rendering engines.

Cookies.

Would have use Netjet.io for all my small projects, saves time for small clients.