A VNC license key is a unique code required to activate and use certain features of the VNC software. The license key is used to verify the authenticity of the software and ensure that it has not been tampered with or pirated. The introduction of the license key allowed RealVNC to offer different tiers of features, with the paid versions providing additional functionality, such as enterprise-grade security, advanced performance, and support.

In response to the licensing changes, some developers have created open-source alternatives to VNC, such as TightVNC and UltraVNC. These projects aim to provide a free and open-source remote access solution, without the need for a license key.

Virtual Network Computing (VNC) is a graphical desktop-sharing system that allows users to remotely control and access the desktop of another computer over a network or the internet. Developed in the mid-1990s by Oliviero Teolato, VNC has become a popular tool for remote access, technical support, and collaboration. While VNC is widely used, its licensing model has undergone changes over the years, leading to the introduction of license keys.