After months of testing and speculation, Google is finally releasing the next edition of Google search to the public, complete with a left-hand menu bar and even an update to the well-known Google logo.

The new version of Google has some major differences, but the changes can be broken down into three groups: design changes, the addition of a left-hand navigation panel and a more “unified” search experience.

The product that is launching today has been the result of countless experiments Google has run, many of which our readers have noticed. Patrick Riley, the technical lead for Google Web Search, told about those experiments and how they ended up in this edition of Google Search.

Design Changes: Simplicity Is Bliss

The first thing most people will notice are the design changes to the home page, search results page and the Google logo.

Here’s what it looks like:

The focus on simplicity hasn’t changed — in fact, that’s why Google created a new edition of the logo, which removes most of the shadow, some of the gradient and even the “TM” symbol at the end.

As Patrick Riley told me, the intention is to go for a cleaner and simpler look across the board. The new Google logo will roll out on Search starting today and will eventually replace all of the other logos on Google’s other properties.

The search results page has also been cleaned up. The traditional blue box that encompasses the search box at the bottom of the search engine results pages (SERPs) has been removed. The underlines under the numbers and several of the links have also disappeared.

Left-Hand Navigation

The design changes aren’t the biggest ones rolling out today, however; it’s the left-hand navigation that is going to be most obvious to users.

Whenever you perform a search with the new interface, the left-hand navigation you see above will appear. The top left should be self-explanatory; it lists the types of searches you can make, such as image search, shopping search and books search.

What you may not realize at first glance is that this is a dynamic sidebar; Google has designed it to change based on the type of search you’re making. If you’re looking for breaking news, Blog and News search is more likely to pop up, while if you search for clothes or shoes, Shopping Search is likely to appear in the list.

Below that section are the query related search tools — things such as related searches, Wonder Wheel, and timeline. Again, this section is dynamic and changes based on the type of search you are making.

Overall, the system is designed to help users refine search results by adapting to their search needs. However, the changes are also meant to “unify” the search experience — when you click on any of the menu items, it doesn’t take you to a completely different looking search results page. The left-hand menu will stay put as you search, which should make it easier for users to navigate the page.

The Experiments Are Not Done

While the new version of Google Search has officially launched, Riley told me that it isn’t the end of the experimentation or of changes to Google’s best-known product. He pointed to the countless iterations of Google over the years, as well as some different designs that the company tested out. Google will continue to run most of its search experiments as it rolls this version to the rest of the world.

What do you think of the new Google design? Are you a fan of the new left-hand nav? Let us know in the comments.