Google is launching an open source web browser to compete with Internet Explorer and Firefox.

The browser is designed to be lightweight and fast, and to cope with the next generation of web applications that rely on graphics and multimedia.

Called Chrome, it will launch as a beta for Windows machines in 100 countries, with Mac and Linux versions to come.

"We realised... we needed to completely rethink the browser," said Google's Sundar Pichai in a blog post.

The new browser will help Google take advantage of developments it is pushing online in rich web applications that are challenging traditional desktop programs.

Google has a suite of web apps, such as Documents, Picasa and Maps which offer functionality that is beginning to replace offline software.

"What we really needed was not just a browser, but also a modern platform for web pages and applications, and that's what we set out to build," Mr Pichai, VP Product Management, wrote.

Competition

The launch of a beta version of Chrome on Tuesday evening (UK time) will be Google's latest assault on Microsoft's dominance of the PC business. The firm's Internet Explorer program dominates the browser landscape, with 80% of the market.

Those already in the browser space were quick to respond to the news.

Writing in his blog, John Lilly, chief executive of Mozilla was sanguine about the new rival in the browsersphere.

"It should come as no real surprise that Google has done something here — their business is the web, and they’ve got clear opinions on how things should be, and smart people thinking about how to make things better."

Chrome will be a browser optimized for the things that they see as important, and it’ll be interesting to see how it evolves," he wrote.

He welcomed the competition and said collaboration between Mozilla and Google on certain projects would continue.

Dean Hachamovitch, general manager of Microsoft's Internet Explorer, was more bullish.

"The browser landscape is highly competitive, but people will choose Internet Explorer 8 for the way it puts the services they want right at their fingertips, respects their personal choices about how they want to browse and, more than any other browsing technology, puts them in control of their personal data online," he said in a statement.

Chrome will be available for download from the morning of Wednesday 3rd September, PST.

At Google, we have a saying: “launch early and iterate.” While this approach is usually limited to our engineers, it apparently applies to our mailroom as well! As you may have read in the blogosphere, we hit "send" a bit early on a comic book introducing our new open source browser, Google Chrome. As we believe in access to information for everyone, we've now made the comic publicly available -- you can find it here. We will be launching the beta version of Google Chrome tomorrow in more than 100 countries.

So why are we launching Google Chrome? Because we believe we can add value for users and, at the same time, help drive innovation on the web.

All of us at Google spend much of our time working inside a browser. We search, chat, email and collaborate in a browser. And in our spare time, we shop, bank, read news and keep in touch with friends -- all using a browser. Because we spend so much time online, we began seriously thinking about what kind of browser could exist if we started from scratch and built on the best elements out there. We realized that the web had evolved from mainly simple text pages to rich, interactive applications and that we needed to completely rethink the browser. What we really needed was not just a browser, but also a modern platform for web pages and applications, and that's what we set out to build.

On the surface, we designed a browser window that is streamlined and simple. To most people, it isn't the browser that matters. It's only a tool to run the important stuff -- the pages, sites and applications that make up the web. Like the classic Google homepage, Google Chrome is clean and fast. It gets out of your way and gets you where you want to go.

Under the hood, we were able to build the foundation of a browser that runs today's complex web applications much better. By keeping each tab in an isolated "sandbox", we were able to prevent one tab from crashing another and provide improved protection from rogue sites. We improved speed and responsiveness across the board. We also built a more powerful JavaScript engine, V8, to power the next generation of web applications that aren't even possible in today's browsers.

This is just the beginning -- Google Chrome is far from done. We're releasing this beta for Windows to start the broader discussion and hear from you as quickly as possible. We're hard at work building versions for Mac and Linux too, and will continue to make it even faster and more robust.

We owe a great debt to many open source projects, and we're committed to continuing on their path. We've used components from Apple's WebKit and Mozilla's Firefox, among others -- and in that spirit, we are making all of our code open source as well. We hope to collaborate with the entire community to help drive the web forward.

The web gets better with more options and innovation. Google Chrome is another option, and we hope it contributes to making the web even better.

So check in again tomorrow to try Google Chrome for yourself. We'll post an update here as soon as it's ready.