On Tuesday, Sun Microsystems Inc. will announce that it will be using its newly minted Common Development and Distribution License open-source license for its long-promised Open Solaris project. However, creating a developer community around such plans to open-source Solaris will not be easy—for many reasons—according to analysts and industry figures.

Sun has long promised that it would open-source Solaris, but it has yet to answer in detail how it will deal with questions about The SCO Group Inc.'s Unix intellectual property claims.

ADVERTISEMENT

"It's hard for me to understand this [Sun open-sourcing Solaris]," said Dan Kusnetzky, IDC's program vice president for system software, back in September. "While Sun prepaid their royalties for Unix a long time ago, they would still agree that it is a derivative work—it is Unix. The SCO Group is the current owner of Unix and is not at all likely to allow its intellectual property to be freely given away under any open-source license."

SCO spokesperson Blake Stowell added at the time: "All I can say is that Sun has the broadest rights of any Unix licensee while at the same time we're confident that Sun knows and understands the terms of that Unix license."

Tom Goguen, Sun's vice president of the operating platforms group, did tell eWEEK's Peter Galli that Sun does not have the legal permission to open-source some Solaris 10 source code. This is mostly third-party specifications and drivers, according to Goguen.

Even if the code is open, Sun's CDDL is not compatible with the GNU GPL (General Public License). "Like the Mozilla Public License, the CDDL is not expected to be compatible with the GPL, since it contains requirements that are not in the GPL," said Claire Giordano, a member of Sun's CDDL team.

The CDDL has other problems for open-source developers as well, according to Mark Webbink, Red Hat Inc.'s associate general counsel. "Some of the license attributes that Sun trumpets actually have the potential of making the software not fully open," he said. "For example, by permitting a different license for the binaries, it will be possible for the binaries to have all of the attributes of proprietary code.

"Here's how this works. The source is made available under the CDDL, but the party building the binaries uses a proprietary compiler that is not readily available and then licenses the binary on a royalty-bearing basis," Webbink said. "Even though they make the source available under the CDDL, the end user would have no ability to replicate the binaries without obtaining a license to the proprietary compiler."

As its first small step to open-sourcing Solaris, Sun will be releasing Solaris' DTrace technology. DTrace is a dynamic tracing framework for Solaris that provides an infrastructure to trace the operating system and user programs' behavior. Sun, however, will not be releasing the compilers and libraries needed to build a functional program from it.

Next Page: Will Sun have a large enough open-source community?