, and it's possible to read it as prohibting, for example, running Open Motif on a privately-modified version of Debian or Fedora.
Richard
Or more applicably to the modern world, perhaps running it in a Docker container that happens to be running on WSL (Windows Subsystem for Linux) would be problematic since the underlying kernel is not open source? To answer a question earlier in the thread, I firmly believe that such usage must be allowed (especially as it involves no "porting" of any nature) in order to qualify as free software.