I searched their wikipedia page (https://en.wikipedia.org/wiki/GnuTLS https://en.wikipedia.org/wiki/GnuTLS) and there are many applications that rely on gnutls:

I searched their wikipedia page (https://en.wikipedia.org/wiki/GnuTLS https://en.wikipedia.org/wiki/GnuTLS) and there are many applications that rely on gnutls: GNOME, CenterIM, Exim, Weechat, Mutt, Wireshark, slrn, Lynx, CUPS, gnoMint, GNU Emacs, Synology DiskStation Manager, OpenConnect