These tools are there to compress your data in the form such that is adjusted in much less space on the hard disk or any storage device. The need for compression tools was felt when the hard disk space was at a premium. At that time the hard disks were to the tune of 120 or even 240 MB. There use to be always storage of hard disk space. Once a file was compressed it would hold only 10% of the actual space of the file. These utilities were really a boom at that time. Even now when the hard disks are available for 4 to 20 GB,still the disk space is left short some times.

Most popular among them is the utility called PKZip and its counterpartPKUnzip or their windows version called WinZip.

PKzip : With this undisputed champion of data compression, one can really think of making BIG use of the available disk space. It compresses and achieves file, saving disk space and reducing file transfer time. It in fact also reduces the decompression time. It almost doubles the valuable disk space by compressing executable files like, COM and EXE files by an average of 45% with virtually transparent operations, all that user notices is more available disk space.

Space Manager : It is another of the disk compression utility which works in perfect tandem with DOS 6.0 and windows to enhance the function and power of DoubleSpace. It is equipped with 6 features that make the program a very usable utility. With space manager you can compress you hard disk, floppy diskette or any storage media, to about 2.2 its original size. Using it you can either maximize the compression of the entire or just selected files and directories. A complete before and after report is printed for you.

Stacker : This is another utility which enables you to double the disk capacity. If one is running DoubleSpace provided by Microsoft as utility with DOS, stacker instantly converts the DoubleSpace drives to the safer stacker drives. It supports all versions of DOS from 3.2 to 6.0.

WinZip : It is as said before the windows version of PKzip. With windows graphics as base, it is more easy to use. It has a button bar and the capacity to drag and drop an archived file to another application.

Zip chunker : Zip chunker from jibben software is not confined to ZIP files alone. One can take any file run it through the software and have a collection smaller file with zip chunker's Own AS extension. Unlike PKzip, zip chunker allows the user to break up an existing ZIP file. Further, archives created with Zip chunker are independent ZIP files. Thus if one has compressed multiple floppies with PKzip, one may need all the floppies it gets a file compressed on just one of them.

Dblspace : This program, which is available with DOS, allows you to compress existing disks and to create new compressed volumes. Once you have compressed volumes, DBLSPACE allows you to manage these compressed volumes and to create new compressed volumes.