Business users of open source software should review their open-source licensing agreements, audit their use, and create formal policies for managing source code, especially mixed-source code.

The effective end of SCO’s attempts to prove its ownership of parts of the Linux code is not the end of licensing issues surrounding open source in the enterprise.

That is the warning of analyst group Saugatuck Technology, which has found that the rapid proliferation of open source software in the enterprise is being mirrored by an explosion in open source licensing types.

This has the potential to present major management problems, Saugatuck warned.

"Given that one of the top four reasons given by user executives (especially SMEs) for adopting Open Source software is the 'Ability to adapt and refine source code,' the likelihood of user enterprises violating or impinging upon multiple license terms increases.

Most IT directors think of open-source licensing as GPL, BSD and perhaps one or two others, but Saugatuck has found there are more than 1,000 types of open-source licences. "That number is likely to increase - as are the complexities of the licences themselves, and the issues regarding licence-compliance."

Saugatuck predicts open-source licensing to extend into multiple formats, to the point where "we will see users of a single solution from one vendor that contains open source code, from multiple vendors being required to comply with multiple licensing terms simultaneously.”

This issue has been highlighted in some open source discussion forums, but it is largely being ignored by IT and business leaders.

In the longer term – after 2010 – the analyst company thinks that the open source community will be able to "bring vendors and users back into a more cohesive community." But the short-term outlook for end users still looks "extremely messy."