I cannot get forge to open!

I download the zipped rar folder but the only thing in it is a file that i cant open, please help?
the name of the file is
"forge-1.2.6.tar.bz2.tar"
the name of the file is
"forge-1.2.6.tar.bz2.tar"
High Quality Resources for Collectible Card Games
https://www.slightlymagic.net/forum/
https://www.slightlymagic.net/forum/viewtopic.php?f=26&t=6922
the tar at the end is a typo, I guess, isn't it?"forge-1.2.6.tar.bz2.tar"
We have changed the archival format used for the Forge distributions from ".zip" to ".tar.bz2". There are utilities for Windows, Mac OS and the various *nix's that can be used to decompress these ".tar.bz2" archives. We recommend that you decompress the Forge archive into a new and unused folder.
Some people use the Windows application 7zip. This utility can be found at http://www.7-zip.org/download.html. Mac users can double click on the archive and the application Archive Utility will launch and extract the archive. Mac users do not need to download a separate utility.