In his Wall Street Journal piece, David Hamilton has done an admirable job explaining Judge Thomas Penfield Jackson's complex Final Judgment in the Microsoft anti-trust case. Unfortunately Mr. Hamilton's article blurs three different senses of "source code disclosure." Only the mildest of these interpretations appears to be mandated by Judge Jackson, and only the strongest fits what the Open Source community means by open source software.

As Mr. Hamilton has stated the matter, one might think that companies competing with Microsoft in the software application market could gain access to the source code for the Windows operating system under certain carefully monitored conditions. In fact, the judge's final judgment only talks about others being "permitted to study... portions of the source code" in the context of disclosure of APIs.

Allowing software developers greater access to Microsoft APIs would certainly help make the software application market more competitive. Open APIs are a critical step towards open standards, and open standards are the minimum step needed to level the playing field. But the judge's ruling does not open the APIs; it only allows controlled access. And even an open API is a far cry from opening the operating system source code.

The main problem with opening the APIs is one of trust. Critics of Microsoft have long maintained that Microsoft has selectively disclosed its APIs to give a competitive edge to is own application developers. Should we rely on government oversight to assure that all the APIs are indeed open? That would be a costly and unproven approach. Government regulation should be an option of last resort. But trusting Microsoft to fully disclose its own APIs will hardlly inspire other application developers to believe they are competing on equal terms.

Even if Judge Jackson were to mandate that Microsoft allow monitored access to the Windows source code, this would fall short of the full disclosure that constitutes open source software. Sun Microsystems, for example, has for years allowed customers access to the Solaris source code under tight licensing restrictions. The momentum behind open source has motivated Sun to loosen those terms, but they have yet to release a version of Solaris that is in fact open source.

The license for truly open source software requires that source code be fully disclosed, and requires that free distribution of that source code be permitted. An open source Windows would inspire application developers to engage Microsoft on truly competitive terms. Yet the most compelling reasons to open up source code are engineering reasons: open source produces better software. Microsoft ought to disclose the Windows source code out of enlightened self-interest. I'm sure that Microsoft understands self-interest. But not even a federal judge can mandate enlightenment. That Microsoft will have to discover on its own.