Compress Files/Folders Greater Than CD

Does anyone know of any software capable of automatically compressing data totaling a sum equal to lets say 4gb to fit a 700mb CD?
I have seen this done, I recently copied the contents of a 698mb CD to my hard drive. After the copy was completed the folder was aproximatly 4gb in size. How was this CD created? :confused:

Clearly you should ask the real creator of this CD content…

Wish I Knew!

Perhaps you should look through this article on compression programs, found here.

This place is a wealth of knowledge!