Although it’s only one system in Figure 1-1 (or two, if you count the thin client), Linux use as a desktop OS is different enough from Linux server use that it requires its own description. Several classes of differences are particularly noteworthy.
Generally speaking, desktop systems require better user interface devices (video cards, monitors, keyboard, and mice) than do servers. Linux usually works well with the same hardware as Windows systems, but with one caveat: the very latest video cards sometimes aren’t well supported in Linux. Staying a generation or two behind the leading edge is therefore desirable in Linux.
Many classes of servers require the very best in disk and network hardware, but this is less often the case for desktop uses. You can often get by with average ATA devices and typical Ethernet (or other network) hardware. Some desktop systems, though, do need excellent disk or network hardware. These are typically high-performance systems that run scientific simulations, specialized engineering software, and so on.
Desktop systems’ needs for powerful CPUs and lots of RAM vary with the application. Generally speaking, modern GUI environments are RAM-hungry, so you should equip a modern desktop system with at least 256 MB of RAM, and probably 512 MB or even 1 GB if possible. Linux does support slimmer environments that can work well in 128 MB or less if necessary, though. Most desktop applications don’t really need powerful 64-bit CPUs, but some programs are written inefficiently enough that a fast CPU is desirable. Also, certain applications are CPU-intensive.
One of Linux’s weakest hardware points as a desktop system is its degree of support for peripheral hardware that’s common on desktop systems but less common on servers, such as scanners, digital cameras, video input cards, external hard drives, and so on. Drivers for all major classes of hardware exist, but many specific devices are unsupported. If you’re buying or building a new system, including such peripherals, you can easily work around this problem by doing a bit of research and buying only compatible devices. If you want to convert existing systems to Linux, though, existing incompatible hardware can drive up the conversion cost.
The distributions outlined earlier, in Section 126.96.36.199, can all function as desktop distributions. Others, such as Mandrake and Xandros, are geared more toward desktop use.
Configuring and administering a desktop Linux system is much like handling a server system, but certain details do differ, mostly related to the specific software used to support each role. You might not even install an SMTP mail server on a desktop system, for instance; instead, you might install the OpenOffice.org office suite. The kernel, the basic startup procedures, and so on are likely to be similar for both types of system.
The terms desktop and workstation have similar meanings in the computer world; both refer to systems that are used by end users to accomplish real-world use. Typically, workstation refers to slightly more powerful computers, to those used for scientific or engineering functions as opposed to office productivity, to systems running Unix or Unix-like OSs as opposed to Windows, or to those with better network connections. The exact word use differs from one author to another, though. I use the two words interchangeably, but I use desktop most frequently.
Traditionally, Linux hasn’t been a major player in the workstation arena; however, it does have all the basic features needed to be used in this way. Over the past few years, Linux’s user interface has been improving rapidly, in large part because of the K Desktop Environment (KDE; http://www.kde.org) and the GNU Network Object Model Environment (GNOME; http://www.gnome.org). These are two desktop environments for Linux that provide a GUI desktop metaphor familiar to users of Windows, Mac OS, OS/2, and other GUI-oriented OSs. These environments rest atop the X Window System (or X for short) that provides low-level GUI tools such as support for opening windows and displaying text. Finally, tools such as office suites (OpenOffice.org, KOffice, GNOME Office, and so on), GUI mail readers, and web browsers make Linux a productive desktop OS. All these tools, but particularly desktop environments and office suites, have advanced substantially over the past few years, and today Linux is roughly as easy to use as Windows, although Linux is less familiar to the average office worker.
Many people think of Linux as a way to save money over using a commercial OS. Although Linux can indeed help you save money in the long term, you shouldn’t blindly believe that Linux will do so, particularly in the short term. Costs in the switch, such as staff time installing Linux on dozens or hundreds of computers, retraining, replacing hardware for which no Linux drivers exist, and converting existing documents to new file formats, can create a net short-term cost to switching to Linux. In the long term, Linux may save money in license fees and easier long-term administration, but sometimes Linux’s limitations can put a drag on these advantages. You’ll need to evaluate Linux with an eye to how you intend to use it on your network.
Appendix B describes in more detail some of the issues involved in using Linux on the desktop.