TightVNC

What TightVNC does

TightVNC is a free implementation of the VNC remote control protocol, distributed under the GNU General Public License version 2. It comes in two halves: a server that publishes the desktop of the machine it runs on, and a viewer that displays and controls that desktop from somewhere else. The distinguishing feature is tight encoding, a compression scheme designed for narrow links, which makes the screen usable over mobile connections and congested networks where an uncompressed stream would stall. On Windows the package installs as a service, can run as an application or in the tray, supports password protection and access control lists, and includes a file transfer tool as well as a Java viewer that runs inside a browser. Unix builds of the same server and viewer are published by the project.

How a typical remote session works

On the machine to be controlled you install the server, set the access password and decide whether it should start with Windows as a service. On your own machine you install the viewer and enter the remote address, optionally followed by a display number and a port. The viewer opens a window showing the remote desktop, and mouse and keyboard input travel back to it. The toolbar offers view-only mode, scaling, clipboard transfer, file transfer and connection settings such as encoding and colour depth. Multiple viewers can attach to one server if it is configured to allow it, which makes the tool handy for a shared look at a single screen. A session ends when the viewer window is closed.

Settings, limits and security notes

The server settings cover the listening port, password, loopback-only restrictions, whether to allow multiple viewers, and per-connection feedback for troubleshooting. The viewer side trades image quality against bandwidth through encoding and colour depth, so a very slow link is best served by reducing colour depth and enabling tight encoding. The important limitation is security: the standard VNC password is short and the protocol is not encrypted on the wire, so a session over an untrusted network should be tunnelled through SSH or a VPN rather than exposed directly. Licences are GPL, which suits free and open projects but is not compatible with shipping the code inside proprietary products without a commercial licence from the vendor.

When to choose something else

If you need to reach a machine behind a home router without arranging port forwarding, a modern remote access service with a rendezvous server saves considerable effort. If you only ever control Windows machines and want the best rendering quality over a fast link, the built-in remote desktop protocol usually feels smoother. If your priority is unattended administration of many servers, a connection manager that stores and groups endpoints will be more comfortable. And if encryption out of the box is a hard requirement, look for a tool that secures the stream by default instead of relying on a tunnel you configure yourself.