Open collaborative design/Free and open-source computer-aided design
One of the core components necessary for open collaborative design to truly take flight is an advanced free and open-source computer-aided design (CAD) program to allow anyone to easily generate new designs or customise existing ones. The program should include a special browser to enable finding and importing open-source components and machines from the 'universal commons' as well as analytical tools and which allow a significant amount of simulation and testing to be done 'virtually', saving significant amounts of time when it comes to construction.
The availability of user-friendly open source CAD software will be essential to allow the widest number of people to engage in this creative activity, which should help create a more diverse ecosystem of objects, machines and solutions. There is no reason, with thoughtful implementation, why this software shouldn't be intuitive enough for children to use easily. It could explain mechanical and engineering principles along the way if the user wished, and also be a place to store detailed contextual development notes, wiki style, to help others understand the workings and decisions made.
The virtual nature of the designs mean that far-flung people via the internet can easily work together on the same design, either working individually on various sub-assemblies of the whole or collaborating directly on the same part. The restrictions of having to finding people local to yourself with similar interests and desires becomes much less of an issue.