ZipLib 2
By:Hasin Hayder
This class can be used to pack multiple files to create a single compressed archive in the .ZIP format.
This class is based on a library known as zip.lib.php written by Eric Mueller, Denis125 and Peter Listiak. It was extended to make it more flexible adding features like adding files listed in an array.
The [...]

ZIPlib
By:Pascal Rehfeldt
You can use this class to add single files, complete dirs or ASCII files as PDF to a ZIP archive.
Download:
http://www.ziddu.com/download/7491484/ziplib-2003-04-14.zip.html

Zip Folder
By:Robert Guerin
This class can be used to extract files and directories from ZIP archives.
It can open a ZIP archive and extract all files restoring the original directory structure.
The class uses the PHP ZIP extension based on the ZZIPlib library that is available from PECL repository.
Download:
http://www.ziddu.com/download/7491462/zipfolder-2006-07-19.zip.html

Zip File

By:Joshua Townsend
This class can be used to create and extract ZIP archives.
It can add and list files and directories in a ZIP archive.
The class uses pure PHP code, so it does not use the PHP ZIP extension.
Download:
http://www.ziddu.com/download/7491424/zipfile-2007-05-03.zip.html

Zip and File Splitter
By:Huda M Elmatsani
When a file is very large size it takes a lot of time to download. A common solution is to zip the file to make it smaller, but if it still too large to download, splitting the file in many pieces is often a better alternative solution.
This class can compress [...]

The Zipa
By: aniel Horvath
This is a simple class that can be used to extract files from a ZIP archive.
It uses the PHP ZIP extension to list all files in a ZIP archive and extract them to the current directory.
Download:
http://www.ziddu.com/download/7491330/zipa-2006-09-28.zip.html

TAR/GZIP/BZIP2/ZIP Archives

By:evin Doucette
Allows the creation of tar, gzip, bzip2, and zip archives, and the extraction of tar, gzip, and bzip2. Supports relative paths/no paths, comments, and recursing through subdirectories. Can write file to disk, allow user to download directly, or return file contents in a string or an array. Does not require any external programs [...]

PHP Zip

Based on “Zip file creation class”, uses zLib
Download:
http://www.ziddu.com/download/7490965/phpzip-2003-03-01.zip.html

Pcl Zip
By:Vincent Blavet
This class can be used to create and extract ZIP compressed archives.
It can create new ZIP archives from a given list files. It can also include and exclude whole directories from the list of files.
The class can also list, extract, duplicate, merge, add or remove files from an existing ZIP archive.
Download:
http://www.ziddu.com/download/7490892/pclzip-2006-09-10.zip.html

Online zip modifier
By:M H Rasel
This class can be used to modify the files in a ZIP archive without creating temporary files in the server.
It is an enhanced version of another class previously written by Joshua Townsend.
This version can open a ZIP archive, extract its contents, add new files, pack the ZIP archive again and serve [...]