Linux FAQs 

Q: What is Linux?

A: Linux refers to any number of UNIX-like computer operating systems that are based on core code developed and controlled by Linus Torvalds.

When most people refer to Linux, they are describing a complete open source operating system that can perform the same functions as a closed source OS like Sun Solaris or Microsoft Windows. Technically, Linux is a kernel and an excerpt from the GNU.org website describes it quite aptly, "Linux is the kernel: the program in the system that allocates the machine's resources to the other programs that you run. The kernel is an essential part of an operating system, but useless by itself; it can only function in the context of a complete operating system. Linux is normally used in a combination with the GNU operating system: the whole system is basically GNU, with Linux functioning as its kernel." For this reason, it is actually more accurate to describe a system like Red Hat Advanced Server as a GNU/Linux system.

Q: What is GNU?

A: The GNU Project is chartered to provide a complete UNIX-like operating system as free software. GNU is sponsored by the Free Software Foundation.

Q: What is open source?

A: Open source software is software that is distributed with its source code, which allows software developers to see the inner workings of the product.

Q: Is all open source software free?

A: While many open source projects are available without a license charge the specific arrangement is left up to the copyright holder. Software distributed under the GNU General Public License is free to use, modify, and redistribute. Software like MySQL provides source code, but requires license fees for commercial distributions.

Q: Can I sell software on a free OS, on Linux?

A: Yes. Vendors like BMC Software, Borland, PeopleSoft, SAP and others have made a commitment to Linux and sell closed-source products for the Linux OS. Companies are free to build and sell commercial applications on Linux, that do not commingle GPL code within their code base. This is why we can build and deliver a commercial version of our software for the Linux platform.

Q: Is Linux the same as UNIX?

A: No. While Linux has features similar to UNIX, it is a separate and unique offering.

Q: What's a distribution?

A: Linux Frequently Asked Questions with Answers provides the most appropriate description:

A distribution is a complete operating system, including the Linux kernel and all the utilities and software you are likely to need, ready to install and use. Most distributions include thousands of software packages, including user-friendly desktops, office suites, and games.

There are a handful of major Linux distributions, and as a beginner you are probably safer using one of them. For information about them, and how they are installed, see the Distributions-HOWTO from the Linux Documentation Project. Also, a list of distributions is updated weekly at http://lwn.net.

Before you select which distribution you want to try, read their descriptions carefully and compare them to your needs. Each distribution is tailored to a particular type of user. Some are optimized to function as servers, some are optimized for gaming, and some are optimized for desktop and office use.

There are a few distributions which are considered to be outstanding choices for new users:

• Red Hat is particularly good for servers
• Mandrake is excellent as a desktop system
• SuSE is also excellent as a desktop system

There are also a large number of releases which are distributed less globally that suit special local and national needs. Many of them are archived at ftp://ftp.tux.org.

Q: Who's Red Hat?

A: Red Hat is currently the market share leader in Linux distributions.

Q: Why is IBM so involved?

A: Because IBM believed that Linux was an important new technology, they saw an opportunity to provide services, hardware, and software around Linux.

Q: Why is Intel so involved?

A: Linux provides an alternative to existing UNIX and Microsoft products that promote the use of Intel's products. Intel has been aggressive in assisting the Linux community, especially with ports to its Itanium family of processors.

Q: What's Apache?

A: Apache is an open source Web server. Apache runs on Linux as well as other operating systems and is the world's most common Web server, powering more than 65% of the world's Web sites.

Q: Why would my client want to use Linux as their database server?

A: Linux is an excellent platform for a database server as it is inherently stable, is fairly secure (no operating system is beyond the human capacity to make mistakes), has excellent built-in logging capabilities, and does not tend to fail-over. In fact, Linux, like NetWare before it, has shown incredible uptime and availability. It also takes advantage of the kernel's multi-threaded capabilities and the ability to dynamically allocate resources as needed. As a server platform, it requires less in the way of coddling from System Administrators, and has an inherently appreciable lower TCO than any of its rivals.

Q: Who's adopting Linux?

A: Businesses of all sizes are adopting Linux. In fact, Gartner Group is reporting that 45% of mid-sized businesses are already using or experimenting with Linux. This figure combined with strong support at the enterprise level indicates that Linux support is broad and expanding.

For more information, visit The Linux Documentation Project today!