What are the difference between OS Commerce 2.2 RC2 and SM2?

[piller]

Hello,

 

Would someone please explain me the differences between OS Commerce 2.2 RC2 and SM2?. Any website link with an explanation would help as well, since I haven't found any yet.

 

I need to install a Shopping Cart solution and I really like OS Commerce, but these two version really confuse me.

 

I really appreciate any help on this.

 

Thanks a lot.

 

Piller