What is COWS Ajax?
You can't do that with Ajax! Quite simply, a new era in web tools is coming. Imagine adding a single line to your web page that allows you to tap into the super cool tools of heavyweights like Google and Yahoo. Of course through COWS Ajax, you could become a heavyweight yourself ;-)
Ajax has been revolutionizing the web. However it is greatly limited by the browser same-origin policy, meaning that your site can only be as good as the web applications and tools that you create. But there's a lot of great tools out there, wouldn't it be nice to tap into them? Changeable Origin Web Services - COWS - Ajax breaks down this barrier. (here's a note on security for you slashdot folks)
COWS in the wild
The first app to use COWS Ajax is SpellingCow. It's a good example as it shows a high degree of interactivity between this page and an app running on a foreign site: impossible with plain Ajax.
Press 'Show Me' to see a live demonstration of interacting with a remote app. It spell checks as you type.
The COWS have come Home
Why is this a big deal? It's Ajax evolved! First you must understand the current limitation, and then you must understand the potential. Rather than sorting through the techno-babble, let's just say that it is currently such a pain to pull off cross-site web applications that it's simply infeasible (installation, maintenance, resources). COWS Ajax makes this cross-site, asynchronous, tri-directional communication (the user, your site, the application host) a no-brainer.
So what's the potential? As evidenced by Google Maps, Flickr, and other web 2.0 goodness, if you make a great app, people will use it and there are certainly ways to make things profitable. With COWS Ajax, cool 3rd party tools can now be created to integrate with your web site. Your users will love the cool tools. You'll happily take the bonus functionality intergrated into your site. And in exchange for making the cool apps, the application host can create branding, drive traffic, or employ serveral revenue streams. Everyone wins! In this case, the cow coming home is the cash cow ;-)