: Use a tool like 7-Zip or WinRAR to open the archive without extracting it. Look for a README.txt or .nfo file inside which often lists features and installation instructions.
If you are trying to understand what this file does, you can use the following methods to identify its "features": Doghump.7z
There is no widely recognized software, library, or public project identified as . : Use a tool like 7-Zip or WinRAR