Linux and the newly openwrt clients are, also their main low level lib (libtelio).. windows/macos are not though
I wonder which VPNs of the ones listed open sourced their backend/server side?edit: Neither Mullvad or Proton have...
it is: https://github.com/NordSecurity/libtelio/blob/main/LICENSE, https://github.com/NordSecurity/nordvpn-linux/blob/main/LICENSE.md
I've been using NordVPN linux cli and I'm actually quite happy with it, good speed and server availability. Also tried Mullvad and is 5* also
I had a torrentleech account which got hacked like 15 years ago