Antitrust settlements are not just meant to punish corporations that abuse their dominant market position; they are also meant to remedy the abuse and restore competition to the affected market. In the real world, this rarely happens. But Samba version 4, released yesterday, could become one of the first open source projects to deliver an effective remedy.

When Microsoft was charged with antitrust violations by a European court in 2004, they agreed to make all the information for network authentication with Active Directory available on fair terms. With substantial effort, the open source Samba project was able to negotiate terms that resulted in documentation becoming available to the project.

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In its efforts to demonstrate compliance, Microsoft went beyond mere licensing to actively support interoperability testing for the new code. Jeremy Allison, one of the core Samba developers, told me:

The documentation created as part of the EU settlement with Microsoft helped us to make the Samba 4 Active Directory Compatible domain controller code robust and reliable when interoperating with Microsoft AD domain controllers. Having Microsoft themselves help in interoperability testing was an added bonus not required by the settlement, but very welcome!

The team behind the Samba file, print, and authentication server suite for Microsoft Windows clients announced the release of Samba version 4 yesterday. This version includes significant new capabilities that offer an open source replacement for many enterprise infrastructure roles currently delivered exclusively by Microsoft software, including acting as a domain controller, providing SMB2.1 protocol support, delivering clustering, and offering a virtual filesystem (VFS) interface. It comes with Coverity security certification and easy upgrade scripts. The release notes include details of all changes.

Notably, this includes the first open source implementation of Microsoft's Active Directory protocols; Samba previously only offered Windows NT domain controller functions. According to the press release, "Samba 4.0 provides everything needed to serve as an Active Directory Compatible Domain Controller for all versions of Microsoft Windows clients currently supported by Microsoft, including the recently released Windows 8."

Samba 4 can join existing Active Directory domains and provides all necessary function to host a domain that can be joined by Microsoft Active Directory servers. It provides all the services needed by Microsoft Exchange, as well as opening up the possibility of fully open source alternatives to Exchange such as the OpenChange project.

These enterprise-strength features pose a significant competitive threat to Microsoft in multiple market segments. Samba is fast and scalable enough for new enterprise deployments, flexible enough to join existing installations, small and low-powered enough for use in embedded applications, and modular enough to offer a source of protocol implementations for new projects needing Microsoft compatibility. As a licensed implementation of Microsoft's protocols, legal risks for users of Samba 4 are likely to be low.

Together, this means a realistic open source exit route from infrastructure lock-in exists for the first time, and OEM integrators needing Microsoft interoperability have an alternative to expensive licensing deals. Could this become the first antitrust settlement in technology to actually result in an effective market remedy?

This article, "Samba 4 threatens Microsoft's enterprise lock-in," was originally published at InfoWorld.com. Read more of the Open Sources blog and follow the latest developments in open source at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.