Ich habe vor einer Weile schon mal irgendwo was zu Bill Gates‘ Standpunkt zum Thema Softwarepatente gelesen. Nein, nicht zu seinem aktuellen Standpunkt, der ist bekannt. In einem Memo hat er 1991 aber überzeugend dargelegt wie Softwarepatente funktionieren:
If people had understood how patents would be granted when most of today’s ideas were invented, and had taken out patents, the industry would be at a complete standstill today. I feel certain that some large company will patent some obvious thing related to interface, object orientation, algorithm, application extension or other crucial technique. If we assume this company has no need of any of our patents then they have a 17-year right to take as much of our profits as they want. The solution to this is patent exchanges with large companies and patenting as much as we can.
Die Patentgeschichte von Microsoft ist in einem Artikel bei ars technica ganz informativ zusammengefasst. Interessante Details:
A patent search reveals that Microsoft received its first patent in 1986. And that patent was not even related to software: it covered a „Holder for storing and supporting articles.“
Das erste Patent wurde also für ein Zwischending aus Aktentasche und Bücherstütze erteilt. Einer der sieben Erfinder die dafür benötigt wurden war übrigens ein gewisser Steve A. Ballmer… 
Microsoft’s first software patent was granted in 1988, and the company held only three software patents by its 15th anniversary in 1990.
[…]
However, beginning in the mid-1990s, Microsoft steadily ramped up its patent filings. Microsoft received its hundredth patent in 1995 and its thousandth patent in 1999. Today, Microsoft has a war chest of over 6,000 patents and is on track to have ten thousand by the end of the decade.
