WorldChanging has a post by Jeremy Faludi on a talk given by Jimmy Wales:
According to Wales, its not primarily a technological innovation, but a social & design innovation. Its elements:
100% free software and content: everyone has the freedom to copy, modify, redistribute, and redistribute modified versions of it and its content.
Neutrality as bedrock principle (skirting philosophical issue of Objective Truth, just getting people to agree that whats written tells a fair story)
Software design which reflects needs of users and has good quality-control features
Security not through user access permissions, but through vigilant users who clean stuff up after vandalism, and easy ways to see when things have been changed.
No set structure of governance–consensus, democracy, aristocracy by reputation, and occasionally a monarchy of Jim are all used to decide issues or settle disputes. They are flexible about the process, because they care more about the results than the process.
He reinforced the vaguely-known wisdom that motivated people will collaborate with whatever tools they have.