Gagging Napster may be the easiest task the RIAA has to face in the war to secure royalties for musicians. That and closing down other file-sharing services with a central server or a known address. Finding other, more secretive operations is where the real challenge lies, and, according to many, it's a war the music industry cannot win. Open source variations on Napster, like Gnutella, which have been developed freely by independent programmers -- look set to take the fight to the RIAA (Recording Industry Association of America). These variations employ sophisticated guerrilla tactics to escape litigation and are emerging as the only way to defend against the music industry's legal efforts. Various file sharing technologies preceding Napster, such as FTP (File Transfer Protocol) and Usenet bulletin-board system have long been a headache for the Net's anti-piracy bodies. While Napster undoubtedly raised the stakes by making files more easy to distribute, it was left vulnerable because it uses a central server to distribute users' files. Programmers have created a multitude of variants and have even reverse-engineered the Napster protocol in order to develop non-Windows versions. Versions exist for BeOS, Linux, BSD and Macintosh. The application has even been written in cross platform languages such as Java, Perl, Visual Basic and Tcl/Tk. The most well known Napster-clone Gnutella, does not require a centralised server to maintain its network and is difficult to trace. The ability to create a 'virtual network' makes tracking it near impossible as there is no central server to locate. Gnutella has also inspired a number of spinoffs including Gnutmeg and iMesh. Other variants like Junglemonkey or Fileswap combine handy realtime chat capabilities with distributed file transfer network. Stealth tactics however, are not the sole strategy available to the technical community: if the RIAA succeeds in shutting Napster's official servers down, there is an open source effort to create Napster-compatible servers, OpenNap which will operate long after Napster disappears. Another application, Napigator, lets Windows users specify which servers they want to communicate with, effectively allowing Napster to function even after the plug has been pulled. Another lesser-known Napster-style project, FreeNet has been designed to be particularly difficult to shut down while at the same time protecting the identity of its users. Developed by British programmer Ian Clarke while at Edinburgh University, Freenet has no central server, but moves information around from node to node without identifying source or destination. Users request information by sending keywords to a node, which then passes them along to adjacent nodes. This carries on until one reports it has a matching file, at which point a copy of that file is passed back along the chain of nodes until it reaches the user. According to Clarke, this makes it virtually impossible to identify individual users or what they are sharing. The newest release of FreeNet, due next week, will even allow users to encrypt exchanged files on their computer. Consensus within the Internet industry suggests these guerrilla tactics will prove too much for the litigious RIAA. Jon Davis, founder of online music site iCrunch.com says dealing with thousands of online hackers creating decentralised sharing utilities will end in defeat, even for the Big Five. "I really don't see how they [RIAA] can deal with systems like Gnutella... these sorts of programs will just keep appearing." Asked if the music industry will ever successfully rid the Internet of file-sharing applications, Davis is unequivocal: "No, I don't think they will." Clarke agrees and suggests the music industry rethink its tactics. "Gnutella would be very hard to shut down," he says. "I basically think that this can't be stopped and that eventually people are going to have to change the way they think about intellectual property." Take me to the MP3 Special What do you think? Tell the Mailroom. And read what others have said.