Users and resellers of RAV AntiVirus, which is especially popular on Linux platforms, are in limbo after Microsoft announced plans to buy the RAV technology from GeCAD Software.

Microsoft has already said that the RAV product line will be discontinued after it completes acquisition of the technology. GeCAD will, however, continue to support its 10 million users worldwide until the end of their contracts.

While Microsoft has claimed that its motives for acquiring the technology is to provide antivirus solutions for its own products and services, the fact that the deal also allows it to kill off a leading tool for protecting Linux-based email servers is an added bonus.

"I don't know why Microsoft bought a Linux company; GeCAD's Windows business is really small compared to its Linux business," said Andreas Marx, an antivirus software expert.

Marx has just completed a test of GeCAD's antivirus software for Linux and concluded that GeCAD "is really the best antivirus solution for Linux".

Microsoft has publicly spoken about the need to fight back against its open source rival, so closing down one of its key antivirus tools is another salvo in its battle against Linux.

The US, Canadian and UK GeCAD resellers we interviewed said that RAV Antivirus for email servers on a Linux platform accounts for the bulk of their RAV sales.

Marx sees the takeover as a big blow to Linux users in particular. "There are alternatives. Users can switch to other antivirus solutions, but it won't be very easy because RAV has many special features," he said. "There is room for a conspiracy theory here. It could be possible that Microsoft wants to stop the solution for Linux."

His assessment is backed up by Michael Katz, president of RAE Internet, the sole US distributor of the RAV product: "In my view, RAV was purchased to add its integrated virus and scan engine to [Microsoft] products. It was probably dirt cheap and maybe Microsoft got the added benefit of sticking it in the side of Linux users."