A day after Sun Microsystems CEO Scott McNealy said open-source software is his company's friend, a prominent advocate of the collaborative programming philosophy has called upon the server maker to open the code of Java.

Eric S. Raymond, president of the Open Source Initiative, said in an open letter Thursday that Sun needs to choose between controlling Java and seeing it spread as widely as possible.

"Sun's insistence on continuing tight control of the Java code has damaged Sun's long-term interests by throttling acceptance of the language in the open-source community, ceding the field (and probably the future) to scripting-language competitors like Python and Perl," Raymond said in the letter.

"The choice is between control and ubiquity, and despite your claim that 'open source is our friend,' Sun appears to be choosing control," he said. "Sun's terms are so restrictive that Linux distributions cannot even include Java binaries for use as a browser plugin, let alone as a stand-alone development tool."

Raymond's remarks were in response to a Wednesday speech in which McNealy said, "The open-source model is our friend." The CEO argued that Sun is better able than competitors to withstand the advent of open-source software, which can be obtained at no cost.