+# Install Firefox plugins.
+# See <https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Distribution_options/Sideloading_add-ons>
+extensions_dir="/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/"
+noscript_xpi="noscript-10.6.xpi"
+url_noscript="https://secure.informaction.com/download/releases/${noscript_xpi}"
+wget "${url_noscript}"
+name=$(unzip -p "${noscript_xpi}" manifest.json | jq -r .applications.gecko.id)
+mv "${noscript_xpi}" "${name}.xpi"
+tridactyl_xpi="tridactyl-1.14.9pre2457-an+fx.xpi"
+url_tridactyl="https://tridactyl.cmcaine.co.uk/betas/${tridactyl_xpi}"
+name=$(unzip -p "${tridactyl_xpi}" manifest.json | jq -r .applications.gecko.id)
+mv "${tridactyl_xpi}" "${name}.xpi"
+mv *.xpi "${extensions_dir}"
+
+# Set up user environments.
+cd "${setup_scripts_dir}"