TigerVNC

A client/server software package allowing remote network access to graphical desktops.

Server
Install tightvnc with the  USE flag enabled:

Client
If you're just installing the client, you will not need the server use flag:

Configuration
Login with normal user:

Kill the running vncserver:

Setup the displays:

Special configuration for KDE (and some others) installed on server
Edit the vnc startup script:

Special configuration for lxterminal installed on server
Edit the vnc startup script:

Special configuration for twm installed on server
Edit the vnc startup script:

Make sure you set the xstartup file to be executable (chmod +x):

OpenRC
Start the server: