Last night at Etech Udi Manber gave me a sneak peek at what Bezos announced this morning - A9's "OpenSearch." A9 has always been more of a "remixable" search engine - with many columns on the right hand side that let you hack your search interface - you can create columns of image, reference, web, and many other types of searches. When I wrote up A9 last year, I imagined that those buttons on the right hand side may well augur a time when any content provider might become a button. Turns out, I was right. But I didn't imagine A9 would use RSS as the way to do it, it's a neat hack. As the tagline to the introduction of the new services states: "We want OpenSearch to do for search what RSS has done for content."

Today Bezos took the stage at Etech and announced an open platform which lets any developer create a searchable column that can be added to A9. In short, if you have a content site, you can syndicate searches of that content through A9. It's all built on RSS, and it's quite easy to do, I'm told. There are already a bunch of new content sites on A9, I imagine many more will be added as news of this spreads. I've added a couple to my page - "Top Blogs" which searches the top 300 or so Technorati sites, and "Sponsored" which basically shows every Adword related to the keyphrase you type in.

"We want to have thousands of these columns," Bezos said.

This is a neat idea, one that I think will evolve and shift over time. What helped me grok it was the idea of a professional, say a doctor, who builds his or her own A9 interface that has traditional web search, as well as a special column for PubMed (MedLine). It lets the doctor remix the search experience to add vertical search results as well as web search into his search interface.

I asked Udi why he didn't have an RSS button for each new column so that we could syndicate new search columns into our RSS aggregators, and he agreed that that should be added, and most likely will be shortly. Also, you can't point to searches as links due to the javascript based interface, which is kind of a bummer.

But the javascript means that the interface for this new feature is very slick - as you use it, it really starts to feel like a desktop OS environment. Just an observation...