DWService is an half (only the client/agent) open source project which offers a service that allows access to remote systems (Windows, Mac, Linux, Raspberry...) using a standard web browser - without any component required on the client side.
TightVNC is a free remote desktop application. With TightVNC, you can see the desktop of a remote machine and control it with your local mouse and keyboard, just like you would do it sitting in the front of that computer.
UltraVNC is easy to use and free software that can display the screen of another computer (via the Internet or a local network) on your own screen. The program allows you to use your mouse and keyboard to control the other computer remotely.
X2Go is an open source remote desktop software for Linux that uses the NX technology protocol.
Dayon! is a user friendly, open-source, cross-platform solution, that allows controlling of remote computers. It can be used as free alternative to various commercial remote desktop and remote assistance products.
TurboVNC is a derivative of VNC (Virtual Network Computing) that is tuned to provide peak performance for 3D and video workloads. TurboVNC was originally a fork of TightVNC 1.3.x, and on the surface, the X server and Windows viewer still behave similarly to their parents.
Connections allows you to connect to and use other desktops. This can be a great way to access content or software on a different desktop operating system. It can also be used as a way to provide support to users who might need help.
WifiMouse is an Android app designed and created by Logan Krumbhaar, a programmer living in Pennsylvania.
The app allows you to use your phone as a remote control for your computer.
WifiMouse vs Microsoft Remote Desktop opinions
It's a mouse app instead of an RDP solution