Last week I had lunch with Joshua Allen and mentioned that I was planning to write a blog post about the game changing effect of some entity adding generally accessible offline support to the AJAX capabilities of traditional web browsers. It seems Jason Kottke has beaten me to writing this with his post  GoogleOS? YahooOS? MozillaOS? WebOS? , he even has a roll call of the usual suspects who might build this and why.

He writes

So who's going to build these WebOS applications? Hopefully anyone with XHTML/JavaScript/CSS skills, but that depends on how open the platform is. And that depends on whose platform it is. Right now, there are five organizations who are or could be moving in this direction:

• Google. If Google is not thinking in terms of the above, I will eat danah's furriest hat. They've already shifted the focus of Google Desktop with the addition of Sidebar and changing the name of the application (it used to be called Google Desktop Search...and the tagline changed from "Search your own computer" to the more general "Info when you want it, right on your desktop"). To do it properly, I think they need their own browser (with bundled Web server, of course) and they need to start writing their applications to work on OS X and Linux (Google is still a Windows company)[4]. Many of the moves they've made in the last two years have been to outflank Microsoft, and if they don't use Google Desktop's "insert local code into remote sites" trick to make whatever OS comes with people's computers increasingly irrelevant, they're stupid, stupid, stupid. Baby step: make Gmail readable offline.
• Yahoo. I'm pretty sure Yahoo is thinking in these terms as well. That's why they bought Konfabulator: desktop presence. And Yahoo has tons of content and apps that that would like to offer on a WebOS-like platform: mail, IM, news, Yahoo360, etc. Challenge for Yahoo: widgets aren't enough...many of these applications are going to need to run in Web browsers. Advantages: Yahoo seems to be more aggressive in opening up APIs than Google...chances are if Yahoo develops a WebOS platform, we'll all get to play.
• Microsoft. They're going to build a WebOS right into their operating system...it's likely that with Vista, you sometimes won't be able to tell when you're using desktop applications or when you're at msn.com. They'll never develop anything for OS X or for Linux (or for browsers other than IE), so its impact will be limited. (Well, limited to most of the personal computers in the world, but still.)
• Apple. Apple has all the makings of a WebOS system right now. They've got the browser, a Web server that's installed on every machine with OS X, Dashboard, iTMS, .Mac, Spotlight, etc. All they're missing is the applications (aside from the Dashboard widgets). But like Microsoft, it's unlikely that they'll write anything for Windows or Linux, although if OS X is going to run on cheapo Intel boxes, their market share may be heading in a positive direction soon.
• The Mozilla Foundation. This is the most unlikely option, but also the most interesting one. If Mozilla could leverage the rapidly increasing user base of Firefox and start bundling a small Web server with it, then you've got the beginnings of a WebOS that's open source and for which anyone, including Microsoft, Google, Yahoo, and anyone with JavaScript chops, could write applications. To market it, they could refer to the whole shebang as a new kind of Web browser, something that sets it apart from IE, a true "next generation" browser capable of running applications no matter where you are or what computer (or portable device) you're using.

So yeah, that's the idea of the WebOS (as I see it developing) in a gigantic nutshell.

I disagree with some of his post; I think desktop web servers are a bad idea and also that the claims of the end of Microsoft's operating system dominance are premature. He is also mistaken about MSN not building stuff for browsers other than IE. Of course, overestimating Microsoft's stupidity is a common trait among web developer types.

However the rest of his post does jibe with a lot of thinking I did while on vacation in Nigeria. I'd suggest that anyone interested in current and future trends in web application development should check it out.