I strongly encourage you to have a look at Chris Penna’s essay on the use of a wiki to create a freely available British Literature open educational resource. This site has been built by multiple cohorts of students over time, and is now a reference work that trumps Wikipedia when searching “British Literature Wikis”.
In the essay, Chris explains the serendipity that lead to what the wiki is today:
While I originally envisioned the site to serve as a student-produced, supplemental handbook for the course, it has evolved beyond the confines of one specific course into a platform for more sophisticated projects by students in the university’s Office of Undergraduate Research Summer Scholars Program, as well as students enrolled in an upper-level English course, “Undergraduate Research.” (page 3-2)
In addition to explaining why he used a wiki for this task instead of discussion forums or blogs, he candidly exposes practices and challenges of working with wikis. By getting his students to engage in writing about British Literature, he watched this resource become more popular over time, getting 200-400 visits per day now.
The use of an open license also adds to the whole package.
Every page in the wiki is licensed under a Creative Commons license. As a result, I have heard from teachers at other institutions who use the wiki in their classes or who have asked for permission to use material from it. One student, who produced an original movie for a page on the background of Victorian literature, reported that the video has been viewed over 13,000 times through her Youtube account and that she has received positive comments there. (pages 3-4 and 3-5)
You’ll see in his essay that there are even more benefits to writing collaboratively in the open. And I might add that doing so adds little to the workload of the instructor if the rules are well defined from the get-go.