Microsoft has completed its acquisition of antivirus software vendor Sybari Software and announced that it will continue selling Sybari's products on a stand-alone basis.

Microsoft will offer a host of Sybari products for Windows, including Antigen for Microsoft Exchange, Antigen for Microsoft SharePoint Portal Server and Windows SharePoint Services, Antigen for Instant Messaging and Antigen for SMTP (Simple Mail Transfer Protocol) Gateways.

At the same time, however, Microsoft will discontinue selling versions of Antigen for Lotus Domino running on Unix and Linux platforms, though the vendor will continue to support current users of those versions.

Not exchange only

Amy Roberts, director of product management for Microsoft's security business and technology unit, called the move a "business decision" since only a "very, very small percentage" of Sybari software is sold for these operating systems. She added that Microsoft will continue to sell Antigen products for Lotus Domino running on Windows, easing concerns that Sybari's software will become an Exchange-only product.

Though Microsoft purchased Sybari primarily as a way to protect users of Exchange, SharePoint portal and SharePoint services from viruses and spam, Microsoft is mulling the possibility that other Sybari software properties might be used across other Microsoft products, Roberts said.

Microsoft originally announced its intention to acquire Sybari in February to provide server-level antivirus security in light of numerous virus attacks against its Exchange e-mail server.

Sybari offers customers a choice of third-party scanning engines rather than providing its own.