Zoo is used to create and maintain collections of files in compressed form. It uses a Lempel-Ziv compression algorithm that gives space savings in the range of 20% to 80% depending on the type of file data. Zoo can store and selectively extract multiple generations of the same file. Data can be recovered from damaged archives by skipping the damaged portion and locating undamaged data with the help of fiz. The FreeDOS project advises NOT using this program with newer DOS systems - Here is a link with more info.