Linux and BSD are two open source operating system families inspired by the 20th-century operating system Unix. Linux is more popular than BSD.

Symbian, which powers most of Nokia's phones, has been shipped in more than 330 million devices worldwide. But in the last few years, Symbian has seen more than its fair share of changes.

It's a topic of fierce debate among high-tech cognoscenti: What's more secure - "open source" code such as Linux and Apache, or proprietary "closed source" operating systems and applications ...

What are some examples of open-source software? Some of the most famous software systems are open source, such as Linux, the operating system that Google’s Android mobile system was built on top of.