This package contains precompiled binaries of Firefox. These are NIGHTLY BUILDS. They are completely untested. We don't even know if they start up without crashing. + It will be installed mainly in /opt/mozilla/firefox-$pkgver, and you can execute 'firefox-nightly' to run it + Maybe it won't work with 64-bit Input Method modules, such as SCIM and iBus. See http://bbs.archlinux.org/viewtopic.php?id=19387 for details.