VNC (Virtual Network Computing) Server is software developed by RealVNC. It allows you to remotely control another computer's desktop. There are several versions:

VNC (Virtual Network Computing) began at AT&T Laboratories as an open-source project under the GNU General Public License (GPL)

No. Any repository claiming to provide valid license keys for commercial VNC software is either fraudulent, out of date, or malicious. Legitimate open-source VNC servers do not require a key.