In 20 years Microsoft has spent more than $14 billion on more than 140 acquisitions and investments, according to an investigation of SEC filings, corporate documents and industry sources conducted by G2 Computer Intelligence. The resulting report, The Microsoft Empire: Roots and All, considers the question of whether Microsoft innovated or bought its way to success. The vast majority of Microsoft's investments have taken place in the last few years, says G2, noting in particular "Redmond's latest penchant has included a slew of minority investments and joint ventures, enough to ensure (or control) the loyalties of companies that remain independent entities." Microsoft's own published information leaves out a lot of detail, and the company's investor relations site doesn't cover the first 15 years at all. That's not when the big money was spent, but G2 notes that it was the "critical period when, among other things, it picked up the technology for Dos, VB and various pieces of Windows --the roots of its eventual dominance of the desktop." We haven't seen the report as yet, but G2 has a good track record of digging in this kind of area, so it's probably money well spent at $45. It can be ordered online here. ®