The prospect has been tossed around tech circles for ages, with various rumors fueling the flame, but the day has finally come -- Google has unveiled its answer to Microsoft dominance.

The search engine giant unveiled its ChromeOS and the first Chromebook notebooks at the its I/O conference this  Wednesday.

The new Web-centric software and PCs are a clear incursion into territory dominated for decades by computers Microsoft's Windows operating systems.

Unlike Windows, which needs to be installed onto computers and requires considerable computing resources and applications to be useful, ChromeOS runs everything from the web.

Google co-founder Sergey Brin has hailed Google's new laptops as a new model of computing.

It's a much easier way to compute, Brin said at the unveiling in San Francisco.

Manufacturers Samsung and Acer have already signed onboard and will release Chromebooks, or laptops based off the new software later this year.

Chromebook is venturing into a new model of computing that I don't think was possible even a few years ago, Brin said.

Ultimately the most precious resource is the user's time. I think the complexity of managing your computer is really torturing users out there. It is a flawed model and I think Chromebooks are a new model and this is the way things are going to be.

The first Chromebooks will be available for order in the US, the UK, France, Germany, Italy, Spain and the Netherlands from June 15.

The price for the Samsung version will start at $430 for a Wi-Fi powered device and $499 for a 3G model. An Acer machine will start at $350.