Going forward, most of the archives on this page will be in 7-zip format. 7-zip files have the file extension .7z. 7-zip is a compression standard developed by Igor Pavlov that has a freely available spec, and is licensed under the GNU GPL license.
The reason why I chose to use 7-zip is because the file size seems to be a lot smaller. The first file I chose to compress in 7-zip was the 2013 Tryzub Ukrainian Stamp Album supplement and it shaved almost 30 MB off the file. The makes it faster for me to upload, and way faster for you to download.
How do you open and use a 7-zip file? Pretty easily.
If you’re a Windows user, the official 7-zip application from http://www.7-zip.org will let you create and extract 7-zip files. As an added bonus, it will do zip, rar and just about any other file format. Best of all, it’s FREE.
On the Macintosh, the free application The Unarchiver will open 7-zip files. The application is available in the Mac App Store.
Keka is also another great choice for MacOS X that will opne 7-zip files.
Stuffit Deluxe for the Mac will also open 7-zip files.
On Linux you should just need to install the package “p7zip” from the package manager your Linux distro uses, and the built in compression and decompression tools of your desktop environment should suddenly be able to deal with 7-zip archives.
The cross platform app Peazip will also work with 7-zip files.