TeamViewer is a beginner-friendly, feature-rich remote desktop management tool that boasts exceptional security features, an intuitive user interface, and a great selection of extra screen sharing and conferencing tools.
Remmina - Remmina is a remote desktop client written in GTK+, aiming to be useful for system administrators and travellers, who need to work with lots of remote computers in front of either large monitors or tiny netbooks.
AnyDesk - AnyDesk is the world's most comfortable remote desktop application. Access all your programs, documents and files from anywhere, without having to entrust your data to a cloud service.
rdesktop - rdesktop is a free and open source remote desktop protocol client designed to make the users able to manage their PCs in a new way.
LogMeIn - LogMeIn gives you fast, easy remote access to your PC or Mac from your browser, desktop and mobile...
KRDC - KRDC is the KDE Remote Desktop Client.
join.me - Instant screen sharing. Instant Aha!