Note: This document descibes how to get source code for older versions of the code, Gecko 1.9.0, Firefox 3 or earlier, and all versions of NSS and NSPR. Development for Gecko 1.9.1/Firefox 3.5 and beyond uses the Mercurial source code control system.

Those doing active development can check out the latest source using CVS. This is the preferred method if you plan to provide patches and fix bugs, as it lets you get up-to-the-minute changes and merge them with your own.

If you want to compile a product for release, it is generally better to Download Mozilla Source Code tarballs.

Getting Started

CVS means "Concurrent Versioning System". To learn more about CVS in general, visit, or read the tutorial.

Anyone can check out (also known as "pull" or "download") the sources via CVS, but only certain people have the ability to check in (make changes, also known as "commit"). Those people are the module owners and their delegates. Read our document on hacking mozilla to find out how to get the ability to check in. You may also wish to read about using SSH to connect to CVS.

While a Full CVS Checkout is also possible, it is not recommended; it puts undue strain on the mozilla cvs server, and should really be avoided unless you know what you are doing, and need it.


To check out the sources, you need to be running CVS 1.11 or later. Furthermore, you must use GNU make to check out and build Mozilla. No other "make" program is acceptable. On windows, mac and regular GNU systems (like GNU/Linux), use "make" to run GNU make; on most non-GNU unixes (like e.g. Solaris, etc.), use "gmake".

CVS Client Settings

The "cvsroot" (repository identification string) used for anonymous access to Mozilla CVS is

To start using CVS you must first log in. Run the following command:

$ cvs -d login
# type the password anonymous

If you are using an IDE, use the following server data:

  • host: ""
  • repository path: "/cvsroot"
  • user: "anonymous"
  • password: "anonymous"
  • connection type: pserver
  • port: default (2401)

Selecting a Project to Pull

Since several different applications are built from the same basic source code, you must choose which application to checkout on the command line using the MOZ_CO_PROJECT variable. This information has to be supplied when it comes to the checkout of the actual source code (see the appropriate checkout section below, according to the branch you want to checkout). The possible options include the following:

The traditional "Mozilla" SeaMonkey suite of browser, mail/news, composer, and other applications.
The standalone "Firefox" browser.
The standalone "Thunderbird" mail/news client.
The standalone HTML composer
The standalone "Sunbird" calendar app.
The next-generation XUL application launcher.
The "Camino" native browser for Macintosh.
Check out sources for all of the above projects

Multiple projects can be specified with commas: MOZ_CO_PROJECT=suite,browser,xulrunner.

Note that if you are using a custom .mozconfig file, you can also specify MOZ_CO_PROJECT there, instead of including it on the command line.

Checking Out a New Source Tree

Check Tinderbox

Before pulling a tree, you should always check the appropriate Tinderbox to make sure that the codebase is not broken. If there are red tinderboxes, it is usually advisable to wait until they are green before pulling a tree.

Branch HEAD

To check out a new source tree from scratch, get the file which contains makefile instructions which are used to pull the rest of the tree:

$ cvs -d co mozilla/

Note: if you have already set up a .mozconfig file, you may also need to check out the following files:

cvs -d co mozilla/browser/config/mozconfig
cvs -d co mozilla/mail/config/mozconfig

Specific Branch

If you want to check out the source code of a specific CVS branch, use

$ cvs -d co -r BRANCH mozilla/

instead. To, for example, pull the Firefox 1.5 development branch, replace BRANCH above with MOZILLA_1_8_BRANCH. For available branch tags in Mozilla, see CVS Tags.

The information on pulling project specific .mozconfig files as listed in the previous section apply to other branches than HEAD as well of course.


After having chosen the correct branch, run:

$ cd mozilla
$ make -f checkout MOZ_CO_PROJECT=option,option

As mentioned above, if you are using a custom .mozconfig file where you have already specified the MOZ_CO_PROJECT variable, you do not need to repeat it here on command line.

Updating a Source Tree

Branch HEAD

In order to update a source tree (being it branch HEAD or a specific branch) to latest branch HEAD, run:

$ cd mozilla
$ cvs up -dA

The -d option adds directories missing from the local tree, i.e. if new directories were introduced on the central repository but were not yet mirrored on the local copy. The -A option removes any "sticky branch" information, which leads to the effect that the tree is updated to HEAD. If you have modified any files on your local tree, but want them to be discarded, simply add the -C option. This overwrites any local chanages.

Specific Branch

To update a source tree which was pulled from a specific branch, use

$ cd mozilla
$ cvs up -dr BRANCH

instead. Replace BRANCH by the tag of the branch you want to update. Options -d and -C can be applied as well.


After having specified the update, you can do the checkout:

$ make -f checkout MOZ_CO_PROJECT=option,option

As always, if you use a custom .mozconfig file where MOZ_CO_PROJECT is already defined, you do not need to repeat it on command line.

Creating a Diff File

In order to create a diff of a single local file against the current file in the repository, use:

$ cvs diff -u8p FILENAME

See Creating a patch for more information.

Converting a Downloaded Source Tree

Downloaded source trees from (source tarballs) are already set up with CVS information, like a normal checkout. You can update these trees like normal trees to the latest code, without special action. See previous section on how to update a source tree.

Full CVS Checkout

While a full checkout is possible, it should really be avoided, and is NOT needed to build any one mozilla client, and really, is not needed to build any combination of clients (considering the webtools/ directory is included). Unless you absolutely know what you are doing, and why you are doing it, this should be avoided at all costs, never-the-less instructions for "how" are included here for completeness

To checkout the entire mozilla source tree (~700MB) run this command (-P option added to not checkout empty directories):

cvs -d -P checkout mozilla


向此页面作出贡献: teoli, ziyunfei, Mgjbot, phenix, Klp99, Pandaren, miaoran2015
最后编辑者: miaoran2015,