What is it? Google’s answer to Twitter? Email and IM replacement? Personal communications and collaboration platform? These were questions and characterizations that emerged as Google announced Wave at the company’s May developer event in San Francisco. (Here’s a bit more context from my related post at the press conference.)

It’s a shapeshifter, a new species and something of a rorschach test for people because it crosses boundaries and isn’t easily defined.

Google Wave’s API has recently become available to developers. And now some first “hands on” impressions are out. Ben Rometsch wrote about his initial experience with Wave — “real-time email. On crack”:

Trying to describe it to my wife last night I came out with “It’s a cross between Messenger, Email and Facebook”. I still think that’s accurate, but it didn’t really help her! Once you start actually using it things slowly fall into place in your mind, but until you do so, it’s pretty hard to explain or understand.

I think it’s more accurate to say that it’s a bunch of shared IM conversations that are organised like email messages and stored on the server for time immemorial. The upshot of all this is that you can use it in a variety of different ways depending on what you want to achieve. It serves as an IM, IRC and Email server, but you can also do things that you might not necessarily first think of, such as using it as a simple Wiki with shared editing and history . . .

This is probably the most advanced ‘application in a browser’ that I’ve seen. It really does feel like a little operating system living in your browser tab. Using it suddenly makes Chrome and Chrome OS make a whole lot of sense. If you listen carefully you can hear Ballmer’s chairs flying around in the background.

I won’t make any grandiose predictions or snarky remarks. From what I’ve seen, however, at a distance it seems pretty interesting.

Related Topics: Google: Apps For Your Domain | Google: Chrome | Google: Labs | Google: User Interface

About The Author: Greg Sterling is a Contributing Editor at Search Engine Land. He writes a personal blog Screenwerk, about SoLoMo issues and connecting the dots between online and offline. He also posts at Internet2Go, which is focused on the mobile Internet. Follow him @gsterling. See more articles by Greg Sterling