Non-CopyLeft, Free licenses such as the BSDLicense: in spirit, "here is the source, do as you please with it".

MicrosoftCorporation doesn't mind CopyCentre licences as much as they hate CopyLeft, because they're allowed to distribute it in BinaryExecutable form without providing the source for their own products. Most of the original MicrosoftWindows TCP/IP stack and utilities was lifted from FreeBSD and (as required by the licence at the time) still contains the "Regents of the University of California" CopyRight notice.