I happened upon Soapbox from Hiveware today. It’s a new blogging tool, but that’s not what interested me. I was interested instead in its unusual construction: it’s a desktop app, installed on your own machine, but it works by running a web server locally, serving HTML as the user interface. Essentially, it’s a web service, running completely on your own desktop.

I’ve seen this paradigm before (the RSS aggregator AmphetaDesk works this way), and wondered about it. At first blush, it seems like nothing more a clever way to allow web-enabled developers to build desktop apps: by running the web server locally, all those web development skills become desktop development skills. But web applications are hard: you spend a lot of effort working against the stateless grain of web servers, and HTML is not great for things like drag-and-drop and multi-paned interfaces.

But thinking about it, I realized there could actually be more important reasons to build apps this way. After all, HTML is the most widely-deployed cross-platform GUI toolkit there is, even if it is not the richest for supporting complex user interactions. Nothing can touch it for cosmetic polish (CSS makes for great skinning). And if what you are building touches on the web, then your UI is already fully web-enabled.

Are there other reasons to work this way? Is there something beyond the power of HTML that I’m missing about the benefits of web-hosted apps that make them compelling even for local deployment?