The following directories are included in the comm-central repository:
build Miscellaneous files used by the build process.
calendar Source code of the Lightning extension and Google Calendar Provider extension.
Files for the chat component of Thunderbird. There is also related code in
common An assortment of code we've uplifted from mozilla-central as it was removed from there.
db The mork database.
editor UI for the Compose window (Thunderbird/SeaMonkey) and the Composer part of SeaMonkey.
ldap The LDAP C SDK. Used for communicating with LDAP servers.
toolkit directories on mozilla-central. Many of the subdirectories follow the same pattern:
content User interface files which become
test Mochitest and/or XPCShell tests.
The subdirectories are:
app Configuration and packaging instructions. Contains
all-thunderbird.js, the default preferences.
base The main mail window and several miscellaneous dialogs. Also, things which are common to many parts of the program.
branding Icons and imagery.
components Various Thunderbird features, including:
accountcreation The account setup wizard.
addrbook The address book user front end. (Not the address book back end, which is in
cloudfile The cloud attachment feature (a.k.a. FileLink).
compose Email composition window.
extensions WebExtensions schema and implementation.
im The chat front end.
preferences The preferences tab.
config Build instructions, including the automation mozconfig files.
installer Packaging and installation instructions.
locales The user-visible strings, in US English. Files from this directory become
test The MozMill user interface tests and the code to run that test suite.
themes Common and platform-specific styling of Thunderbird user interface. Files from this directory become
mailnews Source code specific to the Mail and Newsgroups part of Thunderbird and SeaMonkey.
other-licenses Code that is not under the Mozilla license. See http://www.mozilla.org/MPL/ for more info.
rdf The RDF file format.
suite SeaMonkey specific source code.
taskcluster Files needed for Thunderbird's build infrastructure.
testing Files needed for Thunderbird's test infrastructure.