RealVNC is a server and client application for the Virtual Network Computing (VNC) protocol to control another computer's screen remotely. RealVNC is produced by the company RealVNC Ltd., which was founded by the same AT&T team that created the original VNC program. RealVNC can be seen as a continuation of the original VNC program. RealVNC runs on Windows, Mac OS X (Enterprise edition only), and many Unix-like operating systems (Free & Enterprise editions only). There is also a RealVNC client which runs on the Java platform. There are beta versions of the Enterprise edition for Pocket PC and 'VNC-over-HTTP' tunnelling for Windows and Linux.

VNC has a wide range of applications including system administration, IT support and helpdesks. It can also be used to support the mobile user, both for hot desking within the enterprise and also to provide remote access at home, or on the road. The system allows several connections to the same desktop, providing an invaluable tool for collaborative or shared working in the workplace or classroom. Computer support within the geographically spread family is an ever popular use.

For the individual user, one common scenario is using VNC to help troubleshoot the computer of a distant less-technically-savvy relative. In other words, sitting at your desk in Baltimore, you could use VNC to take control of your relative's PC in California and show them how to install and use some new software package by actually doing it yourself.

A very common business application of VNC is in remote system administration, where it is used to allow administrators to take control of employee machines to diagnose and fix problems, or to access and administer server machines without making a trip to the console. VNC can also be used to provide a flexible hot-desking and road-warrior environment by allowing employees to access their office desktop and server machines from any machine in the company's offices or from other remote sites, regardless of the type of computers involved at either end.

VNC is widely used in educational contexts, for example to allow a distributed group of students simultaneously to view a computer screen being manipulated by an instructor, or to allow the instructor to take control of the students' computers to provide assistance. Of course, as these examples illustrate, the variety of uses of VNC is really as diverse as the many millions of VNC users.