RealVNC - ( Freeware)
Viewing and even controlling one remote computer from another desktop computer is possible with RealVNC which also offer the possibility to do this with computer with different platforms.
RealVNC is a VNC (Virtual Network Computing) customer developed to take control of remote computers, provided that VNC server is running on the remote machines.
User can view and use the remote server with a simple client program from any other computer in the world. One of the main advantages of Real VNC is that computers can have different platforms being possible, for example, to view and control a workstation running Linux from the personal computer with Windows.
# All platforms
* NEW: VNC is available in French, German, and Spanish. The appropriate language for the desktop of each user is automatically selected. This can be changed (if required) using the Locale VNC parameter.
* VNC parameters that parse environment variables (such as LogDir) now resolve the syntax $$ to a literal $, for example to accommodate such a character in a folder name.
* FIXED: The VNC Viewer chat interface no longer prevents a user account password being entered at the Login window or lock screen.
# Windows
* Chat and file transfer are no longer separate applications but rather merged into the vncserverui.exe program. To configure chat and file transfer using Group Policy, examine the VNC Server > mode > User Interface policy folder.
* FIXED: VNC applications can now be run from user accounts with a $ character in the account name.
# UNIX
* VNC Server in Service Mode (vncserver-x11-serviced) and the VNC Server in Virtual Mode daemon (vncserver-virtuald) can now be started using systemctl on Linux distributions that support systemd, such as the latest Fedora.
* VNC Server now supports PAM session modules, and session actions in pam_umask.so, pam_limits.so, pam_env.so, and pam_unix.so are automatically referenced in /etc/pam.d/vncserver (or equivalent file).
* Chat is no longer a separate application but rather merged into the vncserverui program. To configure chat using policy, edit the vncserverui-<mode> policy template file.
* FIXED: VNC hosted on a network share no longer relies on the cacerts.pem file.
# Mac OS X
* NEW: VNC Server in Service Mode can lock the computer or start the screensaver when the last VNC Viewer user disconnects (not available under OS X 10.4).
* The VNC Chat.app no longer reads from the /Library/Preferences/com.realvnc.vncchat.plist file. To configure chat using policy, edit the vncserverui-<mode> policy template file.
* FIXED: VNC Viewer no longer prevents media keys such as volume or brightness from affecting the client computer.