Make React Components With XMLUI, a Visual Basic for the AI Era
If you want to create a user interface for your web application, these days, chances are you’ll use React — or at least, that’s what your frontend developers will likely suggest.
Turns out, that’s the primary reason why Gent Hito, CEO of /n software, decided to target React with his company’s new UI builder product, XMLUI. His frontend developers were React experts, he reasoned, so why not take advantage of that?
“The truth of the matter is that React and React components rule that space,” he explained to me, referring to web interface development. “You know, whether people want to admit it or not, if you want to build componentized web pages that are interactive, it is React. So we said, okay, we got these guys that are great React [developers]. Let them try to make this simple for us.”
Jon Udell, who is a consultant on the XMLUI project, was also on the call with Hito. In his announcement post, he wrote that XMLUI “brings the VB model to the modern web and its React-based component ecosystem.”
The basic gist of XMLUI is that it wraps React and CSS and provides “a suite of components that you compose with XML markup,” as Udell put it.
XMLUI reactivity in action.
Of course, React doesn’t have the best reputation in certain parts of the web development ecosystem. As I’ve written about many times now, React is regularly criticized for its complexity and performance.
Udell is well aware of React’s reputation, but he’s looking at this from a practical perspective. He says that XMLUI can eventually support Web Components or alternate substrates (like Svelte, for example), but first, they need to make sure the current solution works.
“The first thing is, is this the right set of abstractions at the solution builder level,” Udell said. “So that people can do things that they need to get done that look good, come together quickly, and they wouldn’t have been able to do otherwise as easily or as quickly.”
In other words, the React component ecosystem is already thriving, so why not take advantage of that.
However, Hito also emphasized that React is just the starting point for XMLUI.
“What I’ve told to the team is, guys, I don’t care what’s underneath. I’d like to be able to have some definitions that I can potentially translate to other environments. So keep that in mind. Don’t go too deep into the React stuff.”
But Why XML?
When I first saw XMLUI, I was a little surprised that XML was the language being used to wrap React and CSS. Why not use JSON, the format most familiar to JavaScript developers? Or perhaps use HTML templates?
I was shocked to learn that the main reason Hito chose XML was because… the domain name he liked was available.
“It has nothing to do with XML,” Hito told me. “I mean, for the longest time, this thing [XMLUI] was JSON. That’s what the team liked. That’s what the team understood — all the definitions of all the UI elements and forms, et cetera, were in JSON. Then I ran into XMLUI; the domain was available, [it] was 10 bucks.” (Note: currently the .com domain redirects to XMLUI.org, so it seems they own both.)
The project has been four years in the making, but it was only a year ago that they pivoted to XML and the project became XMLUI. It didn’t change the underlying goal, Hito added. “It’s encapsulation of components in a hierarchy that hopefully you understand,” he said.
I had to double-check this: so XMLUI is using XML and not JSON just because of a domain name? Hito smiled and said the intention was to provoke a reaction.
“Brands that position themselves with controversy are powerful,” he said. “And I think it was a stroke of luck that that thing [the domain name] was available; and we picked it up, and we said, hey, why not?”
Sure enough, when XMLUI was launched yesterday, it got onto the front page of Hacker News, where much of the discussion was about the use of XML.
“Actually, I tried to talk him out of it at the beginning,” Udell said, about the XML pivot. “And it turns out this really was, like, I think it was exactly the right thing for this moment.”
XMLUI and the AI Moment
The moment Udell is referring to is the current AI-assisted development paradigm, which he has written a lot about here on The New Stack (among his varied work, he occasionally writes articles for us). As he explained in the XMLUI announcement post, “LLMs don’t ‘know’ about XMLUI out of the box but they do know about XML.”
The idea is that XMLUI will help you create a user interface for an app in a relatively simple manner — there is some scripting required, but not much. But unlike with so-called vibe coding, you will certainly understand the resulting code, so maintaining that app should be easier going forward.
Hito referred to XMLUI as a “semantic layer” on top of the React components.
“…if you set the rules of the game, then you can play with a machine.”
Gent Hito, creator of XMLUI
“It’s a very short vocabulary and very limited things you can do, and the machine behaves,” he said, regarding XMLUI. “And at that level, if you set the rules of the game, then you can play with a machine.”
The implication is that with vibe coding, you (the developer) don’t set the rules and so therefore the output from the machine (the AI) can be incomprehensible to you.
Udell added that he’s already working closely with AI — in his articles, he calls the AI products he uses his “team of assistants” — and so he feels that XMLUI is a complementary tool in that environment.
“My assumption is that anyone who’s trying to use this [XMLUI] in a serious way is likely to be working with an agent — you know, like Claude or Cursor, right? So this is how I operate, like every day… now that’s just my world. I’m seeing the framework and the documentation through the lens of these agents that I’m working with.”
This is why XMLUI comes with its own MCP server, which can bring in external context while you’re working on an app.
A Drag-and-Drop GUI?
In the announcement post, Udell compared XMLUI to a modern version of Visual Basic, a product that “had a rich ecosystem of components.” But that begs the question: will XMLUI get a drag-and-drop user interface, as VB famously had?
Visual Basic 3.0; via WinWorld.
In fact, Hito answered that question before I’d even asked it, in the context of explaining why they chose XML.
“We have a rudimentary GUI tool for building [components], but we want to see how far we can take this with just text. I don’t think it would be appropriate to introduce tools just yet, because they’re going to make that XML unreadable.”
In other words, writing the XML — or, more likely, asking an AI agent to write XML for you — is a key part of making the output of XMLUI understandable.
Another reason perhaps to delay the drag-and-drop GUI is that Hito doesn’t want XMLUI to be viewed as a low-code tool.
“I hate that term,” he said. “I do hate that term, because it ends up usually with just UI tools, drag and drop… that take you up to a certain point, and then just show you the wall. Not that we’re not possibly showing the wall to people, but you can build your own components, right? You can extend it yourself.”
Conclusion
If you’re looking for an easy way to create frontend components, but want something a bit more powerful than a low-code tool, then give XMLUI a go. Who knows, maybe this will bring XML back into fashion — not to mention Visual Basic-style component building.
