Frequently Asked Questions
- What is the difference between "UNIX System" and "UNIX system?"
- What is the difference between Unix and UNIX?
- Is Mac OS X a UNIX system?
- Is FreeBSD a UNIX system?
- Is Linux a UNIX system?
- Is Solaris a UNIX system?
- Why can't the sample code that links against -lbsd compile on my system?
When we speak of the UNIX System itself as an entity, we capitalize the 'S' in System. When we are speaking about a possible implementation of the UNIX System or a particular UNIX system, we use a lower-case 's'.
The Unix operating system was developed at AT&T Bell Laboratories. When AT&T registered the name as a trademark, they capitalized the name to UNIX. Today the trademark is owned by The Open Group. For a system to call itself UNIX, it needs to meet certain criteria, pass conformance tests, and license the name.
As of version 10.5, Mac OS X has been formally certified to be a UNIX system.
While FreeBSD resembles a UNIX system and provides a UNIX-compatible environment, it has not yet been formally certified as a UNIX system. On the other hand, if it looks like a duck, walks like a duck, and quacks like a duck, then it's probably a duck.
While Linux resembles a UNIX system and provides a UNIX-compatible environment, it has not yet been formally certified as a UNIX system. On the other hand, if it looks like a duck, walks like a duck, and quacks like a duck, then it's probably a duck.
Yes, Solaris has been formally certified to be a UNIX system.
The BSD compatibility library might not be installed on your system by default. For example, on Ubuntu, you need to install the libbsd-dev package.