~ % yaourt -Ss firefox-nightly
aur/firefox-nightly 26.0a1-1 [installed: 25.0a1-1] (717)
Standalone web browser from mozilla.org, nightly build
~ % yaourt -Ss firefox-nightly
aur/firefox-nightly 26.0a1-1 [installed: 25.0a1-1] (717)
Standalone web browser from mozilla.org, nightly build