Oh, what could have been. Microsoft M&A executive Fritz Lanman admitted today at Le Web conference in Paris that the software giant tried to buy Facebook."Yeah, we tried to acquire Facebook," Lanman said, according to a TechCrunch report. "Facebook had a lot of similarities to Microsoft back in the day."

One of those similarities, as we pointed out earlier today in the story on Facebook co-founder Mark Zuckerberg pledging the majority of his fortune to charity, was the striking parallel between Zuckerberg and a young Bill Gates.

Chatter of a Microsoft proposal to buy Facebook is not new, but Microsoft execs have not come right out and admitted the buyout attempt to our knowledge. Nonetheless, author David Kirkpatrick provided details of Microsoft's $15 billion offer in his book "The Facebook Effect."

Of course, the deal never came to pass and Microsoft ended up paying $240 million for a 1.6 percent stake in Facebook. At the time, Microsoft was criticized for inflating the Facebook value to $15 billion. But in retrospect it is looking like a good bet given that Facebook is now estimated to be worth some $50 billion.

Nonetheless, Microsoft probably would have liked to have owned the whole thing at this point.