FZip is an Actionscript 3 class library to progressively load standard ZIP compressed files into a Flash movie and extract,decompress contained files on-the-fly, while the archive is still loading.

Fzip is really useful when you want to load many files into your ongoing project such as images for gallery, icons, thumbails btmaps etc

Note that in order to be able to decompress compressed files in a ZIP archive, FZip requires the presence of an Adler32 checksum in addition to the standard CRC32 checksums contained in ZIP archives (this can be readily managed with a few lines of server-side scripting).
FZip was written by Claus Wahlers and Max Herkender
Originally posted by Matteo; For more detail and demo visit these site;

Fzip - http://codeazur.com.br/lab/fzip/
Fzip demo - http://codeazur.com.br/lab/fzip/demo/