Or Microsoft having "Windows" ?
Edit: See also: MS Office, MS Word, MS Security Essentials, and arguably MS Internet Explorer and Windows Explorer (I browse the internet and manage/browse files--there's not much literal "exploring" going on)
You never 'open a window', or 'close a window', or 'change a window'? You might be younger than me (I'm 30) but I've been doing that since having an Atari ST in the last 80s.
Same reason you can buy "linux" laundry detergent.