In a forum thread discussing one persons design it was asked "Maybe we can make an 'open source' kit" ...
I'm all for open source. This web site is run entirely on open source software, and in my day job I'm a leader in the project to open source Sun's implementation of Java. For the last year I've been 100% immersed in planning a large scale open source project, and I will be in this project for the forseeable future. I wanted to outline a bit on what open source means, and would mean for this application.
"Open Source" means a license. The license is one that grants freedoms which are meant to preserve the ability of the public to freely reuse existing designs. Open source software means publishing the software source code. The licenses allow everybody the right to use the software, to modify the software, to redistribute modified versions of the software, all without cost. The licenses do not transfer rights to trademarks, generally.
There's a lot of experience applying this to software. One thing about software design is the work to refine software never ends. But a vehicle design is a little different because there's a point you reach where the vehicle works really well. It's hard to see an ongoing project for a given vehicle design, but it's easy to consider an ongoing project to design the parts of various vehicles. e.g. a range of open source controllers each of which could be used in a range of vehicles. Each controller design would probably reach a finished state, but designing the range of controllers could easily be an ongoing project.
The main model is for a group of people to work together on a common project because they see mutual benefit to do so. You take a project, each person bites off a chunk they can do, they share the results of what they develop, and together they decide on the final result. The process for it varies from project to project .. some projects are led by a dictator, others by a committee, others by consensus, etc. Membership in a project is usually predicated on doing work in the project.
Often the project members are each employees of different companies where each company may be making products out of the project, and the employees are assigned by the company do make sure the project does what the company needs it to do -- to have the quality levels, etc.
So... if a group of people each wanted to build/sell electric bicycles (for example) ...
The group could work together on designs .. share documentation and build plans for the designs .. and each could build their own businesses selling and servicing e-bicycles.
It's different from the proprietary design business model where the businesses try to obscure the design and work in secret etc.