A lot of changes happened in computer world, for example media for saving data.
I remember 5′ diskette for learn lotus and ws followed by 3.5′ diskette, CD era then become alternative for long time data protection.
As demand for saving larger data come we have more option : CD-RW, DVD, removeable harddisk and usb flash disk.
That storage media became small and smaller body with bigger capacity.
Storage media might grow but still can’t satisfy everyone, specially when dealt with larger file vs storage media available.
Here’s the need for file compression software. In linux/unix world there’s a few utilities exist such tar and gzip.
In windows world I list my top 5 favourite compression software :
1. Winzip (http://www.winzip.com)
Since I know windows ( windows Me ) I use winzip for compressing my task also for split file into smaller size to fit my 3.5′ diskette.
The front end easy to understand even for beginner like me 
Winzip provide shareware version with same functionality as registered version. At time of writing winzip version has reach 11.1
Get latest version here
2. Winrar (http://www.rarlab.com)
I found winrar as alternative software for winzip at internet cafe. Different icon but can handle zip file and new format .rar
winrar become important for me when I’m looking for software that able to see content of .iso file without need to burn into cd first.
Same as winrar, but more powerfull I think so
Get latest version here
3. 7zip ( http://www.7-zip.org )
7zip has their own format .7zip beside supporting ZIP, CAB, RAR, GZIP and TAR.
Available in portable version too, which saves my time when going to some place. Put in usb flash disk and I’m ready to fight
Get latest version here for free
4. IZArc (http://www.izarc.org)
Need for powerful version of compression software make hunting new one for our lab school. I can’t describe how this software become top 5.
From author site :
IZArc is the ultimate freeware archive utility supporting many archive formats like: 7-ZIP, A, ACE, ARC, ARJ, B64, BH, BIN, BZ2, BZA, C2D, CAB, CDI, CPIO,
DEB, ENC, GCA, GZ, GZA, HA, IMG, ISO, JAR, LHA, LIB, LZH, MDF, MBF, MIM, NRG, PAK, PDI, PK3, RAR, RPM, TAR, TAZ, TBZ, TGZ, TZ, UUE, WAR, XXE, YZ1, Z, ZIP,
ZOO. With a modern easy-to-use interface, IZArc provides support for most compressed and encoded files, as well as access to many powerful features and
tools. It allows you to drag and drop files from and to Windows Explorer, create and extract archives directly in Windows Explorer, create multiple archives
spanning disks, creating self-extracting archives, repair damaged zip archives, converting from one archive type to another, view and write comments and many
more. IZArc has also build-in multilanguage support.
nothing left to say
Get latest version from here
5. Windows Free ZIP compression
This utilities becomes handy since no need to install and built in software for Windows XP Home and Professional. Save my live often when i forgot my 7zip
portable while winzip, winrar and IZArc not available at the moment.
Do you have favourite compression software that help you a lot ?
Share with us
P.S :
This post is my entry for problogger latest group writing project. Very challenging 
wow, i thought there were only 2 compressions softwares. thanks for the info. i found your post from the problogger project. if you’d like to check my post out, here it is:
http://robinsongo.com/2007/05/08/top-5-tips-to-be-the-next-darren-rowse/