The whole GNU project really is one of the main reasons we still have privacy.

At some point I thought Stallman was a bit too extreme, but now I think https://www.reddit.com/r/StallmanWasRight/

Thanks to GNU we can use Linux, have free encryption with GPG, etc.

Of course other projects like OpenBSD are also great for many things, like LibreSSL, OpenSSH, etc.

And there's also GrapheneOS, lead by Daniel Micay, which brings security and privacy to the mobile world.