In former (CVS) times the T2 source tree was kept in sync using rsync. However nowadays, with powerful version control systems being invented in the meantime, T2 the sources should be accessed using them. The drawback is that you can not get updates with an extracted tar-ball as base - you need to checkout the sources via the version control system. Currently all source trees of T2 are hosted inside a Subversion repository. The command to get the latest sources via Subversion is:
svn co http://svn.exactcode.de/t2/trunk t2-trunk
Alternatively, for example if you are behind a proxy without WebDAV support or you have an account for write access and plan to contribute a lot of changes back, the https:// protocol must be used. Write access is only offered thru an encrypted channel and this also bypasses proxy services.
svn co http2://svn.exactcode.de/t2/trunk t2-trunk
To access a stable tree in favor of the development trunk, just replace trunk with branches/6.0 or an equivalent. You can even checkout tagged released by using tags/6.0.0 - just substitute the version you need.
When you already use Subversion to obtain the source you also have the possibility to switch to another branch or tag while just receiving the changes using the svn switch command.
Let us suppose you have checked out the development trunk but decide you need the controlled stability of the stable trunk: The associated svn command to execute would be:
svn switch http://svn.exactcode.de/t2/branches/6.0
To switch to a specific tagged version you need:
svn switch http://svn.exactcode.de/t2/tags/6.0.3