From Mahara Wiki
This is a release candidate of Mahara 1.0 Sonorus. Release candidates should have no major bugs affecting the installation, upgrade path or general Mahara usage, but nevertheless may have bugs in these areas. You can report bugs to the tracker:
Please choose '1.1 stable branch' as the version of your bug.
In this release, upgrading from the 1.0 stable version is possible. This does not mean that this should be done on a live website! 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:
- A bunch of bugfixes across many parts of the system
- A "register your Mahara" feature, which optionally allows you to send statistics about your site to mahara.org
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.