SeaMonkey 2.53.8 が出た
sudo rm -r /opt/seamonkey* /usr/bin/seamonkey /usr/share/applications/seamonkey.desktop /usr/share/icons/hicolor/*/apps/seamonkey.png
n=2.53.8
wget https://archive.mozilla.org/pub/seamonkey/releases/$n/linux-x86_64/ja/seamonkey-$n.ja.linux-x86_64.tar.bz2 -O seamonkey.tar.bz2
sudo tar xf seamonkey.tar.bz2 -C /opt
sudo ln -s /opt/seamonkey/seamonkey /usr/bin/seamonkey