Google has acquired BumpTop, a Toronto-based tech startup that built a 3-D computer desktop that makes files behave like physical objects.

A September 2009 upgrade to BumpTop added multitouch capabilities to the 3-D desktop that gives files weight and shape, making them behave like physical objects. (CBC) Neither Google nor BumpTop disclosed details of the deal, but the Globe and Mail said the purchase price was believed to be between $30 million and $45 million.

In a post on its website, BumpTop announced it had been acquired by Google and thanked users for their support.

"This means that BumpTop (for both Windows and Mac) will no longer be available for sale. Additionally, no updates to the products are planned," read the note signed "The Bumps."

A free version of the software will be available for download for the next week, BumpTop said.

BumpTop was operating out of Toronto-based venture capital firm Extreme VP. The software originated at the Dynamic Graphics Project at the University of Toronto.

BumpTop originally used pen-based computing, but an update last year incorporated the multitouch support that Microsoft added to Windows 7. A version was also created for Mac OS.

The multitouch upgrade added more gestures to the BumpTop tool kit, including scrunching groups of files into piles, nudging files around with the edge of a user's thumb, and zooming and cropping photos.

With files from The Canadian Press