UltraVNC server runs on Windows and can serve an embedded JavaViewer. UltraVNC README (accessed 5 October 2026).
What it provides
Single Click is a preconfigured server that runs without installation. Single Click does not use the registry. UltraVNC Single Click documentation. The Repeater is a separate application. UltraVNC project site (accessed 5 October 2026).
What you must provide
Make the Repeater accessible from both locations when using it; in Mode II, both ends initiate outbound connections. UltraVNC repeater source (accessed 5 October 2026).
Configure a DSM plugin or a tunnel for encryption: the server default is no DSM plugin. UltraVNC server settings (accessed 5 October 2026).
The official forum lists MS-Logon. UltraVNC forum (accessed 5 October 2026).
Helpdesk components
In the helpdesk pattern, Single Click runs on the end user’s computer as the server. The helpdesk uses the viewer. UltraVNC Single Click documentation describes those roles.
Read Security and remote access best practices before configuring a connection.