XMPP client for desktop.
Gajim also stores your passwords in plaintext. You can avoid this by installing gnome-keyring and python-gnome2-desktop on GNOME or kwalletcli for Kwallet on KDE.
Disclaimer: Using the recommended projects on this site will not guarantee that 100% of your communications will be shielded against surveillance states. Please do your own research before trusting these projects with sensitive information.