Sun is offering a temporary 37% discount on iPlanet to users of IIS or other Web server packages, lowering the per-CPU cost of the software from $1,495 (£1,031) to $940 (£648) until next March. It has also released detailed technical information on how to make the transition and is providing free ChiliSoft software that lets users run some Microsoft Active Server Pages code unchanged on iPlanet-based servers.
Sun officials said the move was inspired by a report released last month by Gartner advising users to consider alternative Web server products after IIS was hit hard by both the Code Red and Nimda worms.
"Microsoft and IIS have taken it on the chin recently," said Evan Quinn, an analyst at Hurwitz Group. "[Sun] sees this as a market opportunity to go out and try to win some business."
But while Sun claims to have made it as easy as possible for users to move to iPlanet, Quinn said doing so will still pose technical challenges.
TruSecure analyst Russ Cooper said many of the security woes affecting IIS-based servers have been caused more by users failing to configure or patch the software properly than by design failures.
For example, both Code Red and Nimda exploited an IIS security hole that could already have been plugged by a patch from Microsoft. Cooper said it may be more cost-effective to better secure existing IIS installations than to replace them with another technology.
Sun's iPlanet trails far behind both the open source Apache Web server technology and IIS in usage, according to a survey conducted last month by UK-based consultancy Netcraft.
Netcraft said it also found that about 150,000 active IIS sites spread over 80,000 IP addresses have been taken offline since the Code Red II worm struck in August. Only 2,000 of those sites have been put back online using a rival Web server product, Netcraft added.
Sun's discount comes a week after Microsoft announced an initiative aimed at making it easier for users to protect IIS and its other products.