RustDesk

Anyone who does tech support for family has seen this: TeamViewer pops up claiming commercial use was detected and kills the session after five minutes. RustDesk exists for exactly that scenario — 120,413 stars, AGPL-3.0, and the fastest-growing project in this category.

Basic usage mirrors TeamViewer: install on both ends, the remote machine shows an ID and one-time password, you type them in and you are connected. No account, no router configuration, NAT traversal handled for you. The installer is only a little over 20 MB and latency is acceptable on ordinary connections.

The real dividing line is self-hosted relays. The official public relay is free and shared, so it slows at peak times, and your session does travel through someone else's machine. RustDesk open-sourced the server side too (hbbs / hbbr): run it on a cheap cloud VM, put your server address and key into the clients, and from then on connections use only your own path, with steady speed and no third party in the middle. It takes about ten minutes and it is the fundamental difference between this and every commercial remote desktop product.

Two practical notes: on Windows, install it as a service if you want unattended access after a reboot; on macOS you must grant Screen Recording and Accessibility permissions in System Settings, or you will be able to see the screen but not control it.

Also, precisely because it enables unattended remote control, never install it at the direction of a stranger. That capability has been abused in phone scams — the tool is fine, but be clear about who you are handing control to.