From Mahara Wiki
This is a beta release of Mahara 1.1 Sonorus. Things will be broken! However,
we are now soliciting bug reports, should you find a bug. You can report bugs
to the tracker:
Please choose 'HEAD/trunk' as the version of your bug.
This release is one in which upgrading from the 1.0 stable
version is possible. This does not mean that this should be done on a live
website! Furthermore, upgrading from this release to any future release will
not be supported either, so please perform any testing you might want to make
on either a new install of this release or a copy of your 1.0 site.
This release includes:
* Formatting of view feedback using bbcode.
* Auto-linking of URLs in html content.
* Bug fixes.
As mentioned above, the upgrade should not be attempted on a live site yet.
Instead, make a copy of your database and dataroot, set up a new Mahara using
them, and test upgrading on that.
Also as mentioned above, upgrading from this release will not be supported.