You find it there:
http://sourceforge.net/projects/unzip-ada/
and there:
http://homepage.sunrise.ch/mysunrise/gdm/unzipada.htm
* Changes in '22', 14-Dec-2007:
- Added a new Compose_File_Name to UnZip.File_System_Routines
see new "-d dir" option in the UnZipAda tool
- Added Zip.Compress, Zip.Compress.Shrink
see the ZipAda tool, which has now the light "Shrink" compression
* Changes in '21', 12-Sep-2007:
- New license: MIT License (more explicit rights, recognized)
- Password permanent over multiple files (bug appeared in v. 20)
Enjoy!
Gautier