Linux is POSIX-compliant (POSIX will be discussed shortly) and portable with versions
available to run cell phones, supercomputers, and most computing systems in
between. Unlike the other operating systems described in this book, its source code is
freely available, allowing programmers to configure it to run any device and meet any
specification. The frequent inclusion of several powerful desktop GUIs continues to
attract users. It is also highly modular, allowing multiple modules to be loaded and
unloaded on demand, making it a technically robust operating system.
Linux is an open source program, meaning that its source code is freely available to anyone
for improvement. If someone sends a better program or coding sequence to Linus
Torvalds, the author of Linux, and if it’s accepted as a universal improvement to the
operating system, then the new code is added to the next version made available to the
computing world. Updates are scheduled every six months. In this way, Linux is under
constant development by uncounted contributors around the world, most of whom have
never met. The name Linux remains a registered trademark of Linus Torvalds.