We have all heard of Wikipedia, the much derided yet ubiquitous and useful website that contains in depth crowd sourced information about absolutely everything. This is the most popular "wiki" on the internet, however many more exist - my favorite ones contain detailed information about every character and episode of a TV series, making complicated shows like "Succession" much easier to watch. These are wonderful because of how "superfans" ensure that the most minute details about the show are included.
For "superfans" and for students, wikis are crowd sourced, real time websites where multiple people can create and collaborate sharing information about a topic or event in an organized, accessible manner.
Teachers are always looking for new ways for students to collaborate in an efficient manner with accountability. By creating a classroom wiki project about a topic, such as the Civil War, students can each take responsibility for creating content in a particular area of the wiki while also reading and editing their classmates' work. They also have the option to extend the assignment by adding additional information about the topic, such as a biography of a Civil War general they became interested in during their research.
Wikis can also be used to create a study resource. For example, in AP US History, students could post a series of most likely essay topics. The first student could write a thesis statement for each topic, then the next student to access the question would have to write a different but equally defensible thesis to demonstrate how many ways a question can be answered.
Finally, wikis could be a great way for a PLC community to share information about how they teach a particular topic. While we talk at meetings, we never end up writing down the various approaches we take to the standards or the our "non negotiables" for each topic. This would be particularly helpful in preparing common assessments because there would be a single source defining the key information all students were taught.