The Unity-2d will not appear in Ubuntu12.10 (with hints at the previous UDS), meaning Ubuntu official will give up Unity-2d. For older devices, you can use the llvmpipe program to ensure Unity compatibility. About Unity-2d: Because Unity must have 3D graphics card support, so some friends without 3D graphics card and friends who use netbook can not use Unity, so Ubuntu officially developed a U for these groups
The Unity-2d will not appear in Ubuntu 12.10 (with hints at the previous UDS), meaning Ubuntu official will give up the Unity-2d.
For older devices, you can use the llvmpipe program to ensure Unity compatibility.
About Unity-2d:
Because Unity must support 3D graphics cards, some friends who do not have 3D graphics cards and those who use netbooks cannot use Unity, therefore, Ubuntu officially developed a version of Unity 2D for these groups, developed using Qt/QML technology, including the core services of Unity.