StuffIt Expander is a file decompressor made by Allume Systems. Although Mac OS X 10.3 and later have full built-in support for both ZIP and DMG files, many Macintosh users still use and prefer Stuffit compression. This means that it may be desirable to have a copy of the free Stuffit Expander installed.

1. Open a Web browser and go to http://www.stuffit.com/mac/expander/.
2. Click Download Now.
3. Register as required and click Submit.
4. Check your email for a message containing download instructions. Follow those instructions to complete the download and install the software.