Patent attacks against Open Source software are nothing new, especially to anyone who has read a press release from SCO or Microsoft in the last few years. Despite the resounding failure of such attacks, proprietary vendors just keep coming up with new ones, and this week it's ClamAV that's under the gun.

That's right, ClamAV — or properly, Clam AntiVirus — the open-source anti-virus solution that runs quietly in the background of many Linux computers, is under attack for patent infringement. And what exactly does the patent cover, you ask? Blocking viruses at the gateway — essentially, keeping the drawbridge up to protect computers on a network. The villains — Trend Micro, of PC-cillin fame — have taken the matter to the International Trade Commission, while Barracuda Networks has stepped up for ClamAV and filed suit in Federal court in Californa.

Groklaw, everybody's favorite Open Source law network, has a call out for prior art — information from before the patent was issued that could invalidate it — so if you love your Clam and don't want to see it get baked, then head over and help out.

Read more.