I have never used NordVPN and have no plans to (happy with Mullvad VPN), but I must credit on two points NordVPN for a recent October 14, 2025 news release titled NordVPN for Linux goes open-source, with the GUI also available via Snap. The first and most obvious point is that it is need NordVPN is “open-sourcing” its graphical client app on Linux. On the second and more subtle point, I appreciate that the NordVPN press release clearly distinguishes the client from non-open source parts of the service under a clear header (What’s changing (and what’s not)):

What’s important to note is the scope. While the GUI and CLI are now open, our core VPN infrastructure, authentication systems, and back-end services remain proprietary.

This is good to see. While no specific examples jump to mind off the top of my head, I recall seeing cases where some part of an application is open source, but he docs or news release does not clearly say that other parts are proprietary. Here, Norton goes the extra step to ensure that there is no confusion about the announcement: “[T]he GUI and CLI [clients] are now open, our core VPN infrastructure, authentication systems, and back-end services remain proprietary.” I hope that other services which feature a mix of open source and proprietary components follow NordVPN’s lead in clearly separating them in their materials.