May '02 Tools

Zip files are special files which have been compressed to take up less room in storage.

What are Zip files?

Downloading files online takes time. The larger the file, the more time it takes. Therefore reducing the size of a file by compression will reduce the download time and will also reduce the amount of storage needed for the file.

Compression is the removal of numbers and characters from the file that can later be added back during decompression. Zip files also act as containers for the various files a program may have. Zip files are indicated by the .ZIP filename extension.

Once you download a compressed Zip file to your hard drive or diskette, you must "Unzip" the file to separate the various components and expand them to their working size. The "Unzipping" is done by using one of the many Unzip programs available. Eight of the top choices are highlighted above.

What is a self-extracting Zip file?

Some Zip files are put together using what is called "self extracting compression". What this means is the file is actually a program. A self-extracting Zip file is an executable program file (.EXE file) that includes a Zip file and software to extract or "unzip" the contents of the Zip file.

Users can run a self-extracting Zip file just as they run any other program. They can extract or "unzip" files from a self-extracting Zip file without running a separate unzip utility or knowing how to use an unzip utility. When the user runs the program it starts the decompression automatically and places the file(s) either in a pre-determined location or in whatever location is designated.

Self-extracting Zip files are particularly suited for distribution of software to beginning users who are not familiar with the concept of Zip files and are easier for end users as they require no special handling. However, since they consist of programs they must be created for a specific platform (operating system). This means that a self extracting program for a Macintosh will not run on a PC and vice versa.

If you don't know what a ZIP file is, you don't want to know, but need to be able to download and install zipped files; there are programs which you can add to your internet browser to download, extract, and install ZIP files for you. One good program for this is NetZip.

What if you're a Macintosh user?

For Macintosh users, a popular compression format is called Stuffit. You can recognize these by the file type of ".SIT". The Stuffit expander is used to decompress them. You can get a copy of Stuffit for Macintosh or PC. Mac ZipIt is a Macintosh program that zips and unzips archives in a format fully compatible with PKZip for the IBM and zip implementations on other systems.