WinRAR is an archive manager with support for packing RAR and ZIP archives and unpacking RAR, ZIP, ZIP64, 7Z (7-Zip), CAB, ARJ, LZH (Lempel-Ziv-Huffman), TAR, GZ, ACE, UUE, BZ2, JAR (Java Archive developed by Sun Microsystems) and ISO (ISO9660) archives. You may use it to backup your data, reduce the size of email attachments, decompress files downloaded from the Internet and create your own file archives.

WINRAR 是現在最好的壓縮工具，界面友好，使用方便，在壓縮率和速度方面都有很好的表現。其壓縮率比之 WINZIP 之流要高。RAR 采用了比 Zip 更先進的壓縮算法，是現在壓縮率較大、壓縮速度較快的格式之一。 主要特點：對 RAR 和 ZIP 的完全支持； 支持 ARJ、CAB、LZH、ACE、TAR、GZ、UUE、BZ2、JAR、ISO 類型文件的解壓；多卷壓縮功能；創建自釋放文件，可以制作簡單的安裝程序，使用方便；強大的檔案文件修復功能，最大限度恢復損壞的 rar 和 zip 壓縮文件中的數據，如果設置了恢復記錄，甚至可能完全恢復等等……

3.70 主要更新：
增加對 Vista 兼容性的更新;
對中文文件名的 ISO 文件的支持更完善;
使用 chm 格式的幫助文件


WinRAR features:

* WinRAR introduces an original compression algorithm.  It allows higher compression ratios than other PC archiving tools, especially for executable files, object libraries, large text files, etc.
* WinRAR offers an optional compression algorithm highly optimized for multimedia data.
* WinRAR supports files and archives up to 9,223,372,036,854,775,807 bytes in size, about 9000PB.  The number of archived files is unlimited for all practical purposes.
* WinRAR provides complete support for RAR and ZIP 2.0 archives and is able to unpack CAB, ARJ, LZH, TAR, GZ, ACE, UUE, BZ2, JAR, ISO, Z, 7Z archives.
* WinRAR supports NTFS file security and data streams.
* WinRAR offers both a classic interactive Windows interface and the command line interface.
* WinRAR provides functionality for creating a 'solid' archive, which can raise the compression ratio by 10% - 50% over more common methods, particularly when packing large numbers of small files.
* WinRAR offers the ability to create and change SFX archives using default and external SFX modules.
* WinRAR offers the ability to create a multi-volume archive as SFX.
* WinRAR offers a number of service functions, such as setting a password, adding archive and file comments.  Even physically damaged archives may be repaired and an archive may be locked to prevent further changes.  Authenticity information may be added for additional security and WinRAR will store information on the last update and name of the archive.

Bugs corrected in Version 3.70 beta 8:

- WinRAR shell extension did not work in Windows NT 4.0;
- when unpacking ZIP archives in command line mode WinRAR returned "write error" (numeric 5) code in situations when it should return "create error" (numeric 9).