I know that developer answered your question but I wanted to say that any file in Linux can in theory be an executable. It is just a toggle in file permission window. If you expected to see a specific file extension for an executable binary, similar to exe on Windows, then you will be disappointed. An executable on Linux can have any extension. They also may NOT have an extension and still be an executable. In fact binaries of the most of the programs on your computer don't have any extension. But some developers put .x86 (for 32bit CPUs) and .x86_64 (for 64 bit CPUs) to executable files to let users know which file should be opened to run the program.