Hall: IBM, Red Hat and Free Software: An old maddog’s view

I suspect you're misremembering what the deal with Cygwin was. It was licensed under the GPL, rather than the LGPL. That had consequences for people who wanted to write proprietary software that linked against the cygwin1.dll. Cygnus, then Red Hat, maintained complete copyright control of the Cygwin source base, allowing the sale of a second license that let people keep their source proprietary.