New Features

Added “Open with” to the contextual menu and changed the View toolbar button to a drop-down button with “Open with” functionality.
You can now specify a custom file extension in save presets.
Added a menu item to extract all archives in a folder recursively.
Added an option and menu item to compress each of multiple dropped items into an individual archive.
Added Japanese (by Koichi Matsumoto) and Polish (by Mariusz Nicpoń) localizations. Thank you, guys!
Added the Greenwich localization framework by Whitney Young, FadingRed LLC to allow super easy translation into new languages. Start BetterZip, hold down the Alt/Option key and drop down the Help menu. There’s a new menu item “Translate BetterZip” that will open the translation interface.

Enhancements:

Increased extraction speed for rar files.
BetterZip will now display exactly which part of a multi-volume rar archive is missing, if any.
In the save panel the standard file extension will be appended to the filename.

Bug fixes:

Fixed a possible crash when quitting BetterZip with the favorites sidebar opened.
Fixed a few errors in the Russian translation.
The registration window could lead to an infinite loop under certain circumstances.
Growl will no longer write a warning message to the log.
Fixed a bug that could lead to files being overwritten when extracting certain tar.gz archives.
 
http://macitbetter.com/version-history/