It is best to download the application package and associated tests together. Then you can be sure that the versions of tests correctly match the build you're running against.
Firefox
The latest Firefox packages are available for nightly and aurora builds. Other builds are available for nightly and candidate builds. You can also find the tinderbox builds, and try-server builds. Depending on which version you want, you might have to look in a subdirectory for the correct files.
The two files you want to download are:
firefox-<version>.<locale>.<platform>.<extension>- Linux (64bit):
firefox-18.0a1.en-US.linux-x86_64.tar.bz - Windows (32bit):
firefox-18.0a1.en-US.win32.zip - Mac:
firefox-18.0a1.en-US.mac.dmg
- Linux (64bit):
firefox-<version>.<locale>.tests.zip- Linux (64bit):
firefox-18.0a1.en-US.linux-x86_64.tests.zip - Windows (32bit):
firefox-18.0a1.en-US.win32.tests.zip - Mac:
firefox-18.0a1.en-US.mac.tests.zip
- Linux (64bit):
Thunderbird
The latest Thunderbird release (candidates) build including the tests can be found here. There are also folders with the latest beta, earlybird and daily builds. You can also find the tinderbox builds, and try-server builds. Depending on which version you want, you might have to look in a subdirectory for the correct files.
The two files you want to download are:
thunderbird-<version>.<locale>.<platform>.<extension>- Linux (64bit):
thunderbird-18.0a1.en-US.linux-x86_64.tar.bz - Windows (32bit):
thunderbird-18.0a1.en-US.win32.zip - Mac:
thunderbird-18.0a1.en-US.mac.dmg
- Linux (64bit):
thunderbird-<version>.<locale>.tests.zip- Linux (64bit):
thunderbird-18.0a1.en-US.linux-x86_64.tests.zip - Windows (32bit):
thunderbird-18.0a1.en-US.win32.tests.zip - Mac:
thunderbird-18.0a1.en-US.mac.tests.zip
- Linux (64bit):