Turning the virtual pages of the Codex Leicester. (Click for larger image.)

In conjunction with the Windows Vista's launch, the British Library launched an online program called "Turning the Pages 2.0" that lets people browse through virtual versions of two Leonardo da Vinci notebooks using some of the underlying graphics technology in the new operating system.

I got a chance to try the program out last week, on a machine running Windows Vista here at work, and I decided it was worth following up on in the paper, since most people didn't hear about it amid all the other Windows Vista launch events. See today's Software Notebook for more.

One of the two featured notebooks, the Codex Leicester, was bought by Bill Gates for $30.8 million in 1994. During the U.K. launch event for Windows Vista (see transcript), he explained why he bought it -- and how he explained the purchase to Melinda Gates:

"I feel very lucky that I own a notebook. In fact, I remember going home one night and telling my wife Melinda that I was going to buy a notebook; she didn't think that was a very big deal. I said, no, this is a pretty special notebook, this is the Codex Leicester, one of the Notebooks of Leonardo da Vinci. And I personally have always been amazed by him because he personally worked out science on his own, and he understood things that no other scientist of that time did. And his work is amazing. He would work by drawing things and writing down his ideas. So he built these notebooks about how light worked, how water worked, how weapons would work. Of course he designed all sorts of flying machines, like helicopters, way before you could actually build something like that. So every one of these notebooks are amazing documents – they're kind of his rough-draft notes of texts that he eventually wanted to put together."

Although the British Library program uses Windows Vista's built-in graphics, it also works after downloading an add-on for Windows XP machines. However, be forewarned that the hardware requirements are relatively steep, and it only works in Internet Explorer on either operating system.