The company, which also announced a biginto the storage market during its analyst conference in San Francisco this week, has three prongs to its Linux plans.
Sun said it will ship a full version of the Linux operating system. It will also expand its line of Cobalt Linux appliances along with a line of low-end, general-purpose Linux/x86-based systems.
The company added it will "aggressively participate in the Linux community," offering key components of its Solaris operating system for free.
The company said more concrete announcements about pricing and product releases will be made in the second calendar quarter of this year.
"This is great for the development community," Chief Operating Officer Ed Zander said on a conference call Thursday. "It brings Solaris developers, which are 300,000, together with Linux developers."
Sun has been participating in numerous open-source projects, lending a hand with the Apache Web server, the Gnome graphical interface software and the Li18nux Linux internationalization effort. Sun also has contributed to the open-source community software such as its StarOffice package that competes with Microsoft Office and Sun's NFS software for sharing files over networks.
But Sun also has alienated some open-source fans by complicating the way it shared source code for Java, Jini and Solaris.
While the company played up expectations that the new Linux developments should increase the market for Solaris, it also emphasized that it will strengthen its move toward open-source environments in general.
"This is an alternative to anyone that wants an alternative to the Microsoft or the IBM environment, which is very controlling," Zander said. IBM also has been moving toward the open-source environment; it announced a new Linux-only mainframe in January.
Red Hat, the leading seller of Linux software and services, hailed Sun's move.
"This is a great day for Linux," said Mike Evans, vice president of business development at Red Hat, in a statement. "Sun is to be congratulated for changing their stance." Evans also said Red Hat looks forward to the contributions Sun will make to the programming community.
Red Hat considers Unix servers from Sun and others its prime customer target.
Sun said on its conference call that its move toward Linux is "bold." But management, which historically has treated Linux as a runner-up to the company's own Solaris, was defensive when analysts questioned whether Sun was tacitly acknowledging that Linux has some superior qualities.
"This is a way to bring Linux applications into the Solaris environment," Zander said. Sun said that although it now lets Linux applications run with Solaris, it has no plans to enable Solaris applications to run with Linux.
"When a Linux application runs in Solaris, you get superior scalability that comes with Solaris," Zander said, noting that Sun will soon be 20 years old, and Linux was developed over time, "modeling after Solaris."