Microsoft Services for Unix and OpenBSD
ubiquitin writes "If you use strings on Microsoft's Services for Unix (SFU) interoperability suite which was developed by Interex you find that it is largely composed of source from the OpenBSD 3.0 source tree according to a recent deadly.org article."
MS has every right to do this with BSD licensed code. And they do with GPLed code to, but if it was GPLed code then they would have to release the source to the derivative product under the GPL.
Note that I'm not making any statements for or against either license, or for or against MS. I'm just pointing the key the difference in these popular licenses.