At the time of writing, the PwnageTool program has been removed as a download available from the official Dev Team page. The file, however, available in several mirror sites that offered to host the download of the file to help the central server invaded by requests. Direct links are located on the home page of the Dev Team.
The tools created by the Dev Team are available for now only for Mac. Recall that the Jailbreak operation allows you to install unofficial programs and firmware on iPhone, while the unlock operation allows you to use iPhone with any SIM card and any operator. The latter is used abroad where iPhone is tied to the carrier that markets it: in our country, unlocking may not be necessary since iPhones sold in Italy already work with any carrier. Recall that the JailBreak operation could void the warranty, finally that some secondary problems are emerging in the posts of the first users: in some systems with PowerPC processor the PwnageTools would not seem to work.