Wesnoth development currently uses the Subversion software tool to keep developers in sync with each other. See the SVN book for more on how to use Subversion.
Browse the code
There are currently two main streams of development: trunk (1.3.x) and branch (1.2.x). Most other branches are only used for a short time to do some testing without disturbing the main development. You can use your web browser to navigate through the source code:
To check out trunk (About 266 MB at october 2006) into a directory wesnoth:
svn co http://svn.gna.org/svn/wesnoth/trunk wesnoth
or to check out the 1.2 branch (About 263 MB at december 2006) into a directory wesnoth-1.2:
svn co http://svn.gna.org/svn/wesnoth/branches/1.2 wesnoth-1.2
More info on the repository: https://gna.org/svn/?group=wesnoth
Do this from inside the wesnoth or wesnoth-1.2 directory where you checked out the repository:
Note that when you update from Subversion, you should always run 'autogen.sh' if configure.ac or any of the Makefile.am files were changed. It is safest to 'make clean' before updating, then update and finally run 'autogen.sh', 'configure' and 'make'.
You may be able to skip the 'autogen.sh' and the 'make clean' if the makefiles and configure.ac have not changed. If only minor changes were made then even the 'configure' step is optional.