Linux is a multi-user, multi-tasking operating system that runs on many platforms, including Intel processors (386 and higher) and DEC Alphas. It implements a superset of the POSIX standard. Linux interoperates well with other operating systems, including Apple, Microsoft and Novell.
The Linux operating system is freely available—it can be copied and redistributed without fees or royalties. The source code for Linux is available on the Internet to anyone who wants it.
For additional information, see http://www.linuxjournal.com/linux/.