I couldn't find any mentions to this compression tool in the forum. It's based on 7-Zip. This is taken from the website: I believe the most important is what it's in bold (by me). I gave it a quick spin the other day. One can only compress either to Zip or 7z formats. It's an OK compression tool, if we want something basic, drag and drop and a nice UI... and free. You can find some screenshots here -http://www.addictivetips.com/windows-tips/hamster-zip-archiver-is-faster-and-more-friendly-alternative-to-7-zip/ There's a newer version.