ARREA integration capabilities are those of SVN (Subversion).
Existing projects not using version control software will benefit from a very easy to understand way of working.
Projects already using SVN or other version control software, such as Mercurial or git, will easily integrate ARREA, as currently most VCS support SVN integration.
An ARREA project can be set up in a new SVN repository or in any folder of an existing SVN repository. An ARREA project can be also linked with other ARREA projects, thanks to the svn:externals SVN property.