A self-extracting Zip file is an executable program file (.EXE file) that includes both a Zip file and software to extract or “unzip” the contents of the Zip file. Users can extract the contents of a self-extracting Zip file by simply running it. This is convenient because the end user does not need an unzip program to extract files from these self-extracting archives. Source: Winzip.com
The file is standalone, and as mentioned above, it is easy to unpack a self-extracting zip file. In most cases you only need to double click on the file to extract the contents.
Buy WinZip 17 Standard. This program creates self extracting zip files.