Sun has started releasing part of Solaris to open source.

Technologies including the kernel and networking software will be available for free usage under Sun's Community Development and Distribution License, said Tom Goguen, Sun's platform software VP.

The kernel includes features such as predictive self-healing and Solaris containers for isolating an application within the operating system. Also part of the release are system libraries and commands.

Users can download source code, combine it with their own source code and make commercial products out of it. "It's a completely royalty-free open source product," Goguen said. "Our goal is to increase and really drive up the ecosystem around Solaris. It's going to be a full, buildable environment. That's perhaps the key thing."

OpenSolaris will run on Intel x86 and 64-bit AMD Opteron systems as well as on Sun's Sparc hardware. Sun hopes to profit by offering support packages to what it hopes will become a more popular operating system. Plus, if open sorucing the OS sees its use increase, Sun hopes it will boost demand for its portfolio of other products.

Goguen did his best to downplay the fact that the move has been forced on Sun thanks to Linux' success by claiming Sun itself was started more than 20 years ago through open source technology - BSD Unix. "[BSD Unix developer] Bill Joy, who was one of the founders of the company, arguably could be considered one of the founders of open source software," is the line.

There are markets underserved by Linux, which lacks the higher uses of Solaris such as self-healing and dynamic tracing, Goguen said. Solaris also offers high-end symmetric multi-processing and offers advantages in addressing multi-core chips. "Red Hat's offering is incapable of scaling as well as Solaris today," Goguen said.

Sun hopes OpenSolaris will stem defections to Linux, said analyst Gordon Haff of Illuminata. "In terms of being sort of the mass-market alternative to Linux, that doesn't seem likely to happen anytime soon. But I think Sun's real focus here is more on its customer base and developer community that are still in the Solaris camp," Haff said.

The move is not likely to attract Windows users because Windows is quite a different system from Solaris, Haff said.

Sun still will offer the commercial version of Solaris, but future commercial releases will be based on the development going on as part of OpenSolaris, Goguen said.

Sun made the dynamic tracing feature of Solaris, known as DTrace, available through open source in January. Some administrative and install technologies will be kept out of the OpenSolaris release on Tuesday.

The OpenSolaris Project plan also calls for future releases of test suites, a tool to manage bug and patch submissions, a code management solution, and design documents.