Jul 1, 2011 11:41 GMT  ·  By

Google has started the biggest redesign in its history, most if not all of its products will get a new coat of paint, following several universal design elements.

The search engine is almost ready, many people are seeing the new version, Maps has the new design already and some of the Google Apps are starting to deploy it as well.

While Gmail is still in testing, Google Calendar has adopted the new design more clearly. It's still not the default, users have to opt in, but it is otherwise fairly complete.

"Google Apps, along with all of Google, will get a new look over the course of the summer to make the user interface more focused, elastic and effortless to use," Simon Smith, Google Apps User Experience lead, writes.

"The first visual updates will be in Gmail and Calendar, and to start they will be available on an opt-in/opt-out basis, so you can continue to use the old interface and preview the changes before they become the default later this year. When you do give it a try, we hope you enjoy a cleaner, more modern look," he added.

With Gmail, the switch was simple, Google simply introduced two new themes which users can switch to, but which are not forced on anyone.

With Calendar, users see a notification informing them of the fresh new look. There's no commitment requirement, users will be able to switch back and forth between the current and the revamped interface at will.

If you feel that the changes are too much, you can hit the gear icon in the top right corner and hit "Use the classic look" to revert to the original. Similarly, if you want to enable the new theme, the option is available in the same spot, just select "Try the new look."