Starting with version 1.1, ZipIt can both compress and decompress files in PKZip 2.0 format, and is fully compatible with PKZip 2.04g, the latest version as of this writing. A new preference has been added to accommodate the new compression technique, called ΓÇ£deflation.ΓÇ¥ In the preferences dialog box, you may now choose to have ZipIt default to either deflation or implosion. If you choose deflation, then whenever you add a file to an archive, ZipIt will default to deflating the file, and will display ΓÇ£DeflatedΓÇ¥ in italics to indicate this. If you choose ΓÇ£ImplosionΓÇ¥, ZipIt will use the old method. When you add a file, ΓÇ£Best GuessΓÇ¥ will be in italics, indicating that ZipIt will use its best guess to choose between implosion and shrinking (in most cases, ZipIt will choose implosion). You may always change the compression method used simply by choosing the new method from the Method menu. Note that ΓÇ£Best GuessΓÇ¥ now means the best PKZip 1.x-compatible compression. Deflation will always be more efficient, but will not be compatible with older versions of unzipping programs.
To summarize: If you want to create the most compatible archives possible, go to the ΓÇ£Preferences->CompressionΓÇ¥ dialog and choose ΓÇ£Default compression: Implosion.ΓÇ¥ If you want to create PKZip 2.0-compatible archives, or donΓÇÖt care about compatibility but want the smallest archives, go to the ΓÇ£Preferences->CompressionΓÇ¥ dialog and choose ΓÇ£Default compression: Deflation.ΓÇ¥ You can always override the default compression by choosing a new compression method from the Method menu.
