Even Microsoft would never claim that their is any misappropriated code in Linux or in any of the major OSS projects, what they are claiming is that they have Patents that cover the concepts used in modern computing.

Of course, MS have never stated with specificity what Patents they feel are being violated; they would rather 'license than litigate' but refuse to tell you what you're buying. Maybe it's because they are a little worried about how those Patents would hold up to scrutiny.

Imagine if someone had patented "A method for the termination of undesired rodents without manual intervention" years ago, what would the state of the Mouse Trap industry be? Even today, 40 Patents per year are granted for Mouse Trap innovations, with over 4,000 Mouse Trap patents on file in total.

I was taught you patent an implementation of an idea, and you get a limited monopoly over the method in exchange for making its workings public. Yes, someone may be inspired by your invention and improve it or do it better - that's the point!

He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. - Thomas Jefferson

The USPTO is broken. The number of Patent applications has increased exponentially during the last decade or two, and Patent examiners rarely have a comprehensive knowledge of the technologies covered in the Patent applications they review.

Patent applicants purposely game the system to keep their patents pending for years, then finally allow these "Submarine Patents" to surface much to the dismay of an entire industry that also made that same Obvious innovation all those years ago.

Until we see real reform in terms of US Patent law and its stifing of innovation in the software industry, the dark cloud of IP litigation will continue to hover over all of us. In the meantime, we can only wait for MS to finally disclose their "evidence" of infringement, and if the SCO case is any indicator, that could be decades.