MP3 player software developer PlayMedia's $20 million copyright infringement suit against its rival, Nullsoft, has been extended to take in MP3.com, mere days after the MP3 music distributor publicly announced its upcoming IPO. PlayMedia's beef with Nullsoft centres on allegations that the latter used code from PlayMedia's Amp in its popular WinAmp MP3 player. The company's case appeared to be strengthened recently when Nullsoft shipped a new version of WinAmp based on the ISO standard MP3 decoder licensed from the Fraunhofer Institute. Nullsoft's moves made it look guilty, but the company said it switched from its original decoder, dubbed Nitrane and the one said to contain PlayMedia code, to the standard version to avoid further legal issues. The Fraunhofer version is probably a more efficient decoder too, but PlayMedia clearly doesn't want to pursue that line of enquiry too far. Meanwhile, MP3.com comes into the picture as one of the most popular sites from which WinAmp can be downloaded. PlayMedia reckons MP3.com has been offering WinAmp since April last year, and is seeking $15 million in compensation as a result. It's not clear why the company has waited so long to sue MP3.com -- its action against Nullsoft was launched in March -- or why it feels MP3.com's support for WinAmp (the site also offers other players for download) is a legal issue. It's not hard to see MP3.com's proposed $115 million IPO as a motivating factor. PlayMedia's line appears to be that the success MP3.com has achieved has largely come about through offering WinAmp, and since that software infringes its copyrights, it's entitled to a cut. Sounds spurious to us, too, but it has to be said, MP3.com did itself no favours by releasing an MP3.com-branded version of WinAmp last year. PlayMedia claims that took place sometime after its CEO, Brian Litman, contacted his opposite number at MP3.com, Michael Robertson, to discuss his allegations against Nullsoft. Fair enough, but Robertson was under no obligation to drop support for WinAmp until PlayMedia' claim is proven -- only then, surely, would he too be guilty of copyright infringement, provided of course he continued to offer the Nitrane version WinAmp for download. That suggests PlayMedia's action is tactical, since presumably it will vanish if the case against Nullsoft collapses. Even PlayMedia proves its case against Nullsoft, it seems a mite unfair battering MP3.com for shipping software in good faith. And the confusion over the timing of the suit is only muddying the water further. MP3.com said late yesterday it still hadn't officially received PlayMedia's suit. The litigant's lawyer, on the other hand, claims it was served on 28 April. ®