FYI: DotNetZip (
http://dotnetzip.codeplex.com), the .NET managed
library for zip files, has recently been enhanced to support a COM
interface. This allows developers using any COM-compatible environment
to build applications that read or create ZIP archives.
DotNetZip does regular zip files, self-extracting archives, passwords,
AES encryption, ZIP64, Unicode, zipfile comments, and more.
You need v1.8 of the library to get the COM stuff.
DotNetZip is free.