From Tomasz Pawlak:
KGB Archiver is free ZIP tool with a very high compression rate. If you are looking for the highest compression free zip software, this is for you. Because of its incredibly high rate of compression, it does have higher hardware requirements (1,5GHz clock and 256MB of RAM) but this should not trouble 99% of you out there. It is also a free encryption software app as it also offers AES-256 encryption which can be used to encrypt the archives. This is one of the strongest encryptions available, and one of the safest. This version is the first release on CNET Download.com.
What's new in this version:
This version is the first release on CNET Download.com.