The commonly available unzip utility can be used to extract files from a ZIP archive. This may be needed to extract the source code from the FWD archive or from some of the other downloaded software (in the case of Windows).

Linux Windows
Install it using sudo apt-get install unzip. Windows does not have the command line unzip.exe tool. To unzip all archive files in ZIP format it is possible to use either Windows GUI zip extractor (zip support is already included in the Windows XP (and above) File Explorer) or if the JDK is already installed the command jar xf can be used as an equivalent to unzip.