The Virtual Forbidden City is,of course,limited in scope; there’s no comparison to Second Life here.However,it has several advantages to using SL.
Accessible on any computer - I have downloaded it to my Acer Aspire One netbook,which would not cope with a full blown virtual world such as Second Life or Twinity.
Rich content:this is unusual for virtual worlds,which are great for truly immersive learning and for social interaction,but have little text,audio or video content of their own
Easy to use:the learning curve with the Virtual Forbidden City is pretty shallow,in part because the avatars are not able to do what would be possible in SL (build,use voice,fly,etc) - that said,there are some activities to do within the 3D environment