>Yes my coders use www.zlib.org zipping/unzipping source code to create our own component, which zip data on server and unzip them in browser. But unzipping require HTTP object, which is blocked by IE if it is on high security level

Ok, I'll keep searching for something that won't have such restriction. My goal is only to zip the file. As for the unzipping, this is up to the user to have an unzipping utility installed that will take over that extension.