The source code is available on a Subversion repository hosted on Sourceforge.net. The URL of the EasyRPG subversion repository is https://easyrpg.svn.sourceforge.net/svnroot/easyrpg/trunk.

For getting it you have several options:

• Do svn co https://easyrpg.svn.sourceforge.net/svnroot/easyrpg/trunk/ DEST_DIR in terminal/console (Change DEST_DIR to the destination directory). You will need to install Subversion first.
• There are many GUI SVN clients, for example: TortoiseSVN on Windows, and RabbitVCS on GNU/Linux. After installing it, do a checkout of https://easyrpg.svn.sourceforge.net/svnroot/easyrpg/trunk in a folder.
• Download a tar.gz with the sources http://easyrpg.svn.sourceforge.net/viewvc/easyrpg/trunk/?view=tar, then unpack the sources somewhere.