In an open letter aimed at Sun CEO Scott McNealy titled “Shame on you, Scott” and published in California’s San Jose Mercury News, a group of dissident customers fired their latest shot in an eight-month spat with Sun.

The dispute started in January 2002 when Sun said it would not support Intel’s microprocessors, based on its x86 architecture, for version 9 of its Solaris operating system. An angry response from customers forced Sun to meet with six representatives of developers, who are referred to as the “Secret Six”, in early 2002.

Sun released Solaris 9 to run on its own Sparc microprocessor-based servers in May 2002. Customers argue that Sun reneged on an earlier promise that Solaris 9 would be ported to Intel’s x86 architecture. Sun denies this, but admits that it has put the project on “indefinite hold”.

Previously Solaris ran on “a wide variety of hardware… from laptops to servers”, but over the past three years Sun has cut back on the number of systems, says John Groenveld, the author of the letter and an associate research engineer at Pennsylvania State’s Applied Research Laboratory. Sun first supported Intel’s x86 microprocessor architecture in 1993 with the release of Solaris 2.1.

Groups of users feel aggrieved because computers that use Intel’s processors typically cost significantly less than those using Sun’s Sparc processors. In addition, many users view Solaris as a good choice for high-performance computing tasks, but regard it as too big and unwieldy for non-intensive applications such as file sharing or email.

Sun appears to favour the open source operating system Linux for such low-end tasks. Since its acquisition of server appliance maker Cobalt it has used a combination of Linux and Intel in its line of low-end email servers. Last month it released its first general purpose server featuring Linux on Intel. However, customers can still buy the server with Solaris 8 installed instead of Linux.