Text-mode logins, as described in Chapter 10, can be handy tools for using or administering a Linux system remotely; however, they're rather limited. Many programsparticularly user-friendly tools to perform common tasks such as word processingrequire the use of a graphical user interface (GUI). Such tools can't be used via a text-mode login alone, although as this chapter describes, using such a tool can be part of an overall remote GUI access plan. If you want to run GUI word processors, web browsers, graphics editors, and other programs remotely, you must use remote GUI access tools. These tools are most important as user access tools because most users today expect GUI environments. They can help provide relatively seamless access to multiple systems from a single keyboard and screen, or they can be part of a thin client configuration, as described in Chapter 12. Remote GUI access can also be used for system administration, either to run GUI administration frontends or to run text-mode programs in xterm or similar windows. (In the latter case, though, a simpler solution is usually to access the system via a text-mode login protocol.)
The features, requirements, and potential uses of GUI login tools are somewhat different from those of text-mode login tools, so these factors require some explanation, and this chapter begins with this topic. This chapter then moves on to the traditional Linux remote access tool, the X Window System (or X for short), which Linux also uses to manage its local GUI display. Next up is information on a popular alternative, Virtual Network Computing (VNC), which can be used to access either Linux or Windows systems remotely.