The shareware application CompactPro can compress Mac files, taking up about half as much disk space. Extracting (decompressing) these files is a few clicks away.
Double-click on the CompactPro icon to launch the application.
Step2
Select Open from the File menu (or press Command-O).
Step3
Select the file or archive you want to extract (decompress) from the directory window. Its name will appear in an archive window.
Step4
Click on the filename.
Step5
Click on the Archive menu and select Extract (or press Command-E). Your file or archive will decompress to its original size, at which point you can use it.
Tips & Warnings
If the file is a "self-extracting" archive (it will have the extension .sea), just double-click it to open it.