: The original software for this format. While it is trialware, the "evaluation" version allows you to extract files indefinitely. It is available at WinRAR's Download Page .
While does not appear to be a standard or widely documented software package in official databases, it is a RAR archive file —a high-quality compressed format often used to bundle multiple files or large data sets into a single, smaller package.
To see what is inside the archive, you will need an extraction utility.