Virtual network computing

Abstract

T he so-called network computer (NC) aims to give users access to centralized resources from simple, inexpensive devices. These devices act as clients to more powerful server machines that are connected to the network and provide applications, data, and storage for a user's preferences and personal customizations. We have taken this idea a stage further. In the virtual network computing (VNC) system, server machines supply not only applications and data but also an entire desktop environment that can be accessed from any Internet-connected machine using a simple software NC. Whenever and wherever a VNC desktop is accessed, its state and configuration (right down to the position of the cursor) are exactly the same as when it was last accessed.In contrast to many recent Internet applications, which have focused on giving users access to resources located anywhere in the world from their home computing environments, VNC provides access to home computing environments from anywhere in the world. Members of the Olivetti & Oracle Research Laboratory (ORL) use VNC to access their personal Unix and PC desktops from any office in our Cambridge building and from around the world on whatever computing infrastructure happens to be available-including, for example, public Web-browsing terminals in airports. VNC thus provides mobile computing without requiring the user to carry any device whatsoever. In addition, VNC allows a single desktop to be accessed from several places simultaneously, thus supporting appli-VNC is an ultra-thin client system based on a simple display protocol that is platformindependent. It achieves mobile computing without requiring the user to carry any hardware. *Andy Hopper is also affiliated with Cambridge University Engineering Department.cation sharing in the style of computer-supported cooperative work (CSCW).The technology underlying VNC is a simple remotedisplay protocol. It is the simplicity of this protocol that makes VNC so powerful. Unlike other remote display protocols such as the X Window System and Citrix's ICA, the VNC protocol is totally independent of operating system, windowing system, and applications (see the sidebar, "Thin Clients"). The VNC system is freely available for download from the ORL Web site at http://www.orl.co.uk/vnc/.We begin this article by summarizing the evolution of VNC from our work on thin-client architectures. We then describe the structure of the VNC protocol, and conclude by discussing the ways we use VNC technology now and how it may evolve further as new clients and servers are developed.

UCSF Chimera—A visualization system for exploratory research and analysis

“…Given these considerations, application-independent collaboration tools are not as responsive for sharing molecular modeling sessions. Such desktop-sharing applications (e.g., Microsoft NetMeeting and Virtual Network Computing 40 ) function by transmitting the contents of the screen from the workstation running the application to all who are sharing it. This can be bandwidth-intensive, especially for molecular graphics, where most operations alter a large amount of screen content.…”

Using Provenance to Support Real-Time Collaborative Design of Workflows

“…One of the most general and common methods of real-time collaboration is through remote desktops like VNC [9]. By using this in the design of a workflow, users can see each others operations like dragging modules around and creating connections.…”

Interacting at a Distance Using Semantic Snarfing

“…This is related to the idea of PalmVNC [15], but we supply more features to make it easier to interact on the handheld. In Grabber, the user can control the level of zooming.…”

“…Closely related to the snarfing of pictures is the VNC system [15], which displays the screen from one computer on another. The user can operate the remote screen by clicking on the local picture.…”