Capitalizing on recent criticism of Microsoft's Web server software, a British company will announce a product Monday that it says can enhance the security of the Microsoft offering or replace the program altogether.

Zeus Technology is releasing Zeus Web Server 4.0, an update of its flagship software, which has never been hacked, according to Andrew Parker, principal consultant at Zeus.

"We've never had a security breach," he said. "It was built from the ground up with security in mind."

Zeus is the latest company to appeal to users of Microsoft Internet Information Server (IIS) software running Web servers after several nasty computer viruses spread throughout the Internet in August and September. The Code Red and Nimda viruses were infecting thousands of computers running IIS, which is used to power Web pages.

Two weeks ago, Sun Microsystems announced it would slash the price of its iPlanet Web server software by 37 percent in an attempt to take market share from Microsoft.

The viruses also prompted Gartner analyst John Pescatore to recommend that affected IIS customers move to other Web server software that is not so prone to virus and other security attacks, such as iPlanet or the free Apache Web server.

Even before the viruses hit, insurance underwriter J.S. Wurzler's Safeonline division said it would charge some IIS users up to 15 percent more in premiums to make up for the perceived increased risk of the Microsoft product.

But it can be expensive and time-consuming to switch to new software. Because a company's Web server is often closely linked with other applications and databases, it is not easy to replace it with new software, experts said.

In addition, IIS Web site engineers are usually trained to work on the Windows operating system and may have to learn Unix, Parker noted.

"There is a lot of complexity and cost to migrating," said Stacey Quandt, an analyst at Giga Information Group. "However, the long-term benefits, to a large degree, will outweigh the costs."

Zeus says its software is not only more secure than other Web server products but also three times faster and can support 10 to 100 times as many transactions and communication requests.

Corporations can use Zeus to provide enhanced security to their IIS servers now or move over to Zeus on its own. For example, eBay has moved its heavily used auction search site from IIS to Zeus, although its main Web page is still powered by IIS, according to Parker.

"An organization may feel that, in the current economic climate, they just want to fix the immediate problem (of security)," he said. "If they feel a longer-term Unix solution would be better, we'll provide a migration path."