RAR is somewhat of a legacy format in terms of compression ability but RAR remains popular in many places especially for its split archive feature. Current Fedora users are used to installing unrar command line utility from RPM Fusion to get the ability to extract RAR files and unrar is supported by the GNOME (File Roller) and Ark (KDE) archive managers however it is a proprietary utility and unavailable for other architectures like ARM which are getting popular in Fedora as well.
Free software support for RAR files was considered a high priority FSF project which announced that it has been completed a while back. It took sometime for the support to become more solid and I have built a package for Fedora. In Fedora 19 or newer, users can use unar from the Fedora repository. unar is the free and open source command line utility for RAR archive extraction from the Unarchiver project. All the RAR features including encrypted archives are fully supported by this utility. unar is supported as an alternative to unrar by File Roller however Ark support is still under review. I pushed a update of File Roller that automatically pulled in unar but this was reverted due to lack of space in the live image however if you do install it, File Roller will use it. I have filed a bug report against unrar in RPM Fusion to consider automatically replacing it with unar and we will have to figure out when it is suitable to do so. I highly recommend users try unar if you need to extract RAR files and use the open XZ format with better compression for creating new archives.