WinRAR and the RAR file format have evolved over time. Support for the archive format RAR5, using the same RAR file extension as earlier versions, was added in version 5.0;[13] files in the older RAR file format have since been referred to as RAR4. WinRAR versions before 5.0 do not support RAR5 archives;[2] only older versions of WinRAR run on Windows versions prior to XP, and cannot open RAR5 archives.