Search giant Google has unveiled Google Wave, a system aimed at improving online collaboration, and has provided preview versions to developers at the Google I/O Conference taking place in San Francisco.

Google software engineering manager and ex-Google Maps guru Lars Rasmussen pointed to previous communications advances such as email and instant messaging as the starting point for Google Wave - essentially, asking the question: "What would email look like if we developed it today?".

"With Google Wave, we're proposing a new communications model, and after more than two years, we're very eager, and a little nervous, to see what the world might think," he said.

Google hopes Wave will cause a re-think about what a single communications platform might look like when started from scratch, but with access to the online technologies people take for granted today.

Wave will allow multiple users to exchange real-time dialogue, photos, videos, maps, documents and other information forms within a single, shared communications space known as a "wave".

Users of the system should be able to see instantly what fellow collaborators are typing and even publish a wave to a blog or web site, where the content will update instantly as the wave changes. Google said the aim is to allow people to communicate and work together in a richer, more instant and integrated way.

Google Wave will introduce features such as concurrent rich text editing, whereby users will be able to see, "almost instantly, letter-by-letter, what fellow collaborators are typing into a message or document in a wave," according to Rasmussen

There will also be a playback feature, and Google said the technology can integrate with the rest of the web. "Developers can build extensions to Google Wave using our open APIs, embed waves in other sites, or build applications that interoperate with Google Wave, " said Rasmussen.

Google also said it was planning to open source Google Wave in the coming months.