One is a fully-functional live CD, like the one included in Mandriva Linux 2006 Discovery or the old Move, but it also includes a wizard which quickly and easily installs One to the hard disk from within the running system. From then on you can use it just like a normal installed Mandriva system. One is built on the latest Community edition of Mandriva Linux 2006, which means it includes all updates and bug fixes made available since the initial release of 2006, so it's more stable and bug-free than ever. The first beta of One is now available from the Mandriva public mirrors (in the /devel/iso/2006.0 subdirectory): since it's built on top of Mandriva 2006, the actual software it contains should be stable and reliable, but this is the first public test for the new live CD system and especially the live installer, so please focus your testing on these areas! Bugs can be reported to the normal Bugzilla , please remember to pick Mandriva Linux 2006 One as the distribution when reporting bugs. Happy testing!
Note that there are four editions of One each with a different selection of languages. The names for the editions are self-explanatory, except possibly "Occident", which covers English and other Western European languages.