Stephen O’Grady and Simon Phipps have both recently published interesting posts on the current state of open source, with Stephen pondering the relative growth of open source and Simon wondering whether the “commercial open source” bubble has burst.

What they are describing, I believe, is the culmination of the trends we predicted at the beginning of 2009 for commercial open source business strategies – specifically the arrival of the fourth stage of commercial open source.

What is the fourth stage of commercial open source? In short: a return to a focus on collaboration and community, as well as commercial interests.

Open source 1.0 was characterized by software developed by communities of individuals and academia, with key projects including Apache, GNU, the Linux kernel, PostgreSQL and BSD Unix.

Open source 2.0 was characterized by vendors beginning to engage with those existing developer communities, specifically the various Linux distributors that emerged, as well as the involvement in Linux, Apache and other projects by systems vendors such as IBM, Sun and HP.

Seeing the opportunity to disrupt existing markets with open source licensing a group of entrepreneurs created the vendor-dominated open source development/distribution projects that would come to epitomize open source 3.0: MySQL, JBoss et al.

The rapid growth of these companies and the rapid adoption of their software briefly allowed people to believe that the golden age of open source would see closed source vendors replaced by open source alternatives. However, that potential required a compromise.

While the first two stages were focused on collaborative development as a by-product of open source licensing the projects and vendors that characterized the third stage were focused on market disruption through widespread distribution and typically eschewed the potential advantages of collaborative development in favour of control over the future development of the project.

There have been plenty of debates recently about whether this is the “right” approach to open source. While I would continue to maintain that collaborative development is neither necessary or guaranteed for open source software it is clear that the lack of collaborative development is potentially sub-optimal for both vendors and users/customers.

That was why we predicted increased emphasis on collaborative development for non-differentiating code in the stage 4.0 of commercial open source.

While we previously expected this to be characterized by formal, “vendor-dominated development communities” such as Eclipse and Symbian it has become clear that the process is much more fluid, and the participants are not necessarily vendors.

The agreement between Rackspace and NASA on OpenStack is of course an example of that. We would also see evidence in the involvement of Facebook, Twitter, Linkedin, Digg and others in the various NoSQL database projects, as well as Hadoop.

We have also seen other corporate contributions to open source from non-vendors, particularly in the animation space where the likes of Sony Image Pictureworks recently teamed up with Industrial Light & Magic on the Alembic computer graphics interchange format.

For that reason I would now define stage 4.0 of commercial open source as characterized by corporate-dominated development communities.

Vendors still have a role to play, of course, but the emphasis is on collaboration and community rather than a control. We see evidence of open source 4.0 in the increased number of vendors emerging around community-developed projects.

It is in the context of open source 4.0 that we also argued that open core vendors should consider releasing the source code for their core open source project under a more permissive license, or better still via an existing community/foundation.

While we have not seen any vendors take the plunge as yet, we have seen Alfresco launch the Activiti business process management project with a view to moving to a more persmissive license, while it has also launched its Alfresco Community Committer Program.

We would also see signs of open source 4.0 in Adobe’s acquisition of Day Software. While previous open source-related M&A deals have prompted consideration of the value of community, that was usually in the context of the value of a community of users that could be potentially cross-sold. With Adobe/Day it is clear that there was (at least some) value in Day’s relationship and involvement with the Apache community.

We would also see evidence in the increasing number of closed-source vendors and service providers adoption complementary strategies for engagement with open source software. To update one of our previous statements: if open-core was a significant revenue strategy of open source 3.0, then expect the various complementary strategies to be the dominant revenue strategies of open source 4.0.

While these companies remain reliant on closed source software to generate revenue the fact that they do not attempt to generate revenue from open source software directly enables them to engage in collaborative development projects in which all participants are able to benefit mutually from their collective efforts.

This is not going to result in the displacement of closed source providers by open source specialists but it may be the optimum balance of open source licensing and commercial business strategies. From that perspective this may well be the start of the golden age of open source.

We explain more about our theory of the evolution of commercial open source in Control and Community, the follow-up to our Open Source is Not a Business Model report, which is now available. The report provides more context for the economic motivators and issues involved in the various models, as well as updated research on which vendors are following which strategies, and why, as well as a survey of 286 open source software users to uncover what they make of it all. The report will be freely available to CAOS subscribers. For more details of the CAOS research practice, and to apply for trial access, click here.