Really impressed with 7-Zip

Update Aug 20, 2011:  Just found out that 7-Zip can also extract CD/DVD image files (.iso). Nice! Below are all the file formats it supports:

• Packing / unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP and WIM
• Unpacking only: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR and Z.

I have been using Winzip to compress files for as long as I can remember. One of my colleagues mentioned another compression tool called 7-Zip to me a couple of weeks ago and I am really impressed with the high compression ratio achieved by 7-Zip. Besides it's free and supports all compression file formats (.zip, .rar, .gz, .7z) that I know of. Below is a chart that compares the compressed file sizes between Winzip 10 and 7-Zip 4.65 on several files that I use for my daily work:

File	Uncompressed	.zip	.7z	%smaller
Virtex-6 UG365	15.8MB	5.4MB	4MB	26%
ADEPT 0.38.6	12.6MB	5.3MB	4.4MB	17%
SP601 Base Reference Design rdf0003	56.3MB	17.5MB	10MB	43%