Creative Commons licenses is 3.0 now

New CC license has four parts:
Share:
The licensor permits others to copy, distribute, display, and perform the work beyond the freedoms given by fair use.

Remix:
Licensor permits others to make derivative works beyond the freedoms given by fair use.

NonCommercial:
The licensor permits others to copy, distribute, display, and perform the work. In return, licensees may not use the work for commercial purposes without permission beyond the freedoms given by fair use.

ShareAlike:
The licensor permits others to copy, distribute, display, and perform the work. In return, licensees may not use the work for commercial purposes without permission beyond the freedoms given by fair use.

The new thing is Remix, which is allow others to derivative works. When in CC 2.5, ShareAlike is ask others not change works. But in CC3.0 it is just ask keep the same CC license when modify the works.

CC Labs