7-Zip是一款GNU/LPGL协议下分发的免费软件,可以说是目前最有希望成为zip、rar之后的下一个主流压缩格式的文件压缩格式了.7Zip 的 压缩率是他最大的竞争优势,在选择普通压缩率的情况下我们已经可以轻松击败WinRAR的最高压缩率了.但是7zip也不完美,主要是软件的界面依然不够优秀,格式本身对于分卷压缩的支持也不好,但是这不妨碍7zip成为最有潜力的压缩格式.下载：
7-Zip for 32-bit Windows: 
http://dl.7-zip.org/7z903.exe 
 
7-Zip for 64-bit Windows x64: 
http://dl.7-zip.org/7z903-x64.msi 
 
What's new after 7-Zip 9.02 alpha: 
- 7-Zip now can update solid .7z archives. 
- Some bugs were fixed. 
 
What's new after 7-zip 4.65: 
- 7-Zip now can update solid .7z archives. 
- 7-Zip now supports LZMA2 compression method. 
- 7-Zip now supports XZ archives. 
- 7-Zip now can unpack NTFS, FAT, VHD and MBR archives. 
- 7-Zip now can unpack GZip, BZip2, LZMA, XZ and TAR archives from stdin. 
- 7-Zip now can open/copy/compress disk images (like .c:) from . folder. 
- 7-Zip File Manager now doesn't use temp files to open nested archives  
stored without compression. 
- New -scrc switch to calculate total CRC-32 during extracting / testing. 
- Some bugs were fixed. 
 
Don't use this alpha version for important data. Call "Test" command after each compressing operation.