The Encyclopaedia Britannica has announced that it will allow online contributions from scholars and readers. All contributions will be vetted before becoming public.
Here's an excerpt from the announcement:
The Britannica Online site will become the hub of a new online community that will welcome and engage thousands of scholars and experts with whom we already have relationships. . . .
To elicit their participation in our new online community of scholars, we will provide our contributors with a reward system and a rich online home that will enable them to promote themselves, their work, and their services; allow them to showcase and publish their various works-in-progress in front of the Britannica audience; and help them find and interact with colleagues around the world. In this way our online community of scholars not only will be able to interact with our editors and content in a more effective manner; they will also be able to share directly with Britannica’s visitors content that they may have created outside Encyclopaedia Britannica and will allow those visitors to suggest changes and additions to that content. . . .
Readers and users will also be invited into an online community where they can work and publish at Britannica’s site under their own names. Interested users will be able to prepare articles, essays, and multimedia presentations on subjects in which they’re interested. Britannica will help them with research and publishing tools and by allowing them to easily use text and non-text material from Encyclopaedia Britannica in their work. We will publish the final products on our site for the benefit of all readers, with all due attribution and credit to the people who created them. The authors will have the option of collaborating with others on their work, but each author will retain control of his or her own work. . . .
Two things we believe distinguish this effort from other projects of online collaboration are (1) the active involvement of the expert contributors with whom we already have relationships; and (2) the fact that all contributions to Encyclopaedia Britannica’s core content will continue to be checked and vetted by our expert editorial staff before they’re published.
Read more about it at "Encyclopaedia Britannica Goes—Gasp!—Wiki."